Fixing `sendMessage` Errors: `whatsapp-web.js` Evaluation Failed

by Admin 65 views
Fixing `sendMessage` Errors: `whatsapp-web.js` Evaluation Failed

Introduction to whatsapp-web.js: Powering Your WhatsApp Automation Journey

Hey there, fellow developers! If you're diving into the exciting world of WhatsApp automation, chances are you've stumbled upon whatsapp-web.js. Trust me, this library is a game-changer, allowing us to programmatically control WhatsApp Web and build some truly amazing bots, automated customer support systems, notification services, and so much more. It's built on top of puppeteer, which is Google's browser automation library, giving whatsapp-web.js the superpower to interact with the WhatsApp Web interface just like a human user would. We're talking about sending messages, receiving messages, handling media, managing contacts – the whole shebang! The potential for innovation here is huge, and that's why so many of us rely on this fantastic tool to bring our ideas to life. It opens up a universe of possibilities for personal projects and business applications alike, making routine tasks feel effortless and allowing us to scale our communications in ways that would be impossible manually. From simple birthday reminders to complex CRM integrations, whatsapp-web.js stands as a robust foundation for modern digital communication strategies. Its flexibility, coupled with the power of Node.js, makes it an indispensable asset in any developer's toolkit, constantly evolving to meet new demands and challenges in the messaging landscape.

However, as with any powerful tool that interacts with a constantly evolving platform like WhatsApp, we sometimes hit a snag. One of the most perplexing and common errors that can stop you dead in your tracks, especially when you're trying to perform the most fundamental action – sending a message via client.sendMessage – is the dreaded Evaluation failed: b at ExecutionContext._ExecutionContext_evaluate. If you've seen this pop up in your console, you know that sinking feeling. It's like your bot was ready to conquer the world, and suddenly, it just… stops. This isn't just a minor glitch; it's a message from the JavaScript execution context within the browser that something fundamentally went wrong when whatsapp-web.js tried to run a script. It's a sign that the underlying automation logic, which is crucial for functions like sendMessage, couldn't be completed successfully in the browser environment that puppeteer controls. This error, while cryptic at first glance, is often a symptom of compatibility issues, changes in WhatsApp Web's internal structure, or even subtle misconfigurations in your setup. But don't you worry, guys, because in this comprehensive guide, we're going to break down exactly what this Evaluation failed error means, why it happens, and most importantly, how to diagnose and fix it so you can get your sendMessage function back on track and your bots communicating effectively again. We'll go deep into troubleshooting, explore common pitfalls, and share best practices to ensure your whatsapp-web.js journey is as smooth as possible. So, grab a coffee, and let's conquer this challenge together!

Deep Dive into the Evaluation Failed Error: What's Really Going On?

Alright, let's get into the nitty-gritty of that gnarly error message: Evaluation failed: b at ExecutionContext._ExecutionContext_evaluate. When you encounter this Evaluation failed message, especially originating from ExecutionContext._ExecutionContext_evaluate, it basically means that puppeteer, which whatsapp-web.js uses under the hood, tried to execute some JavaScript code inside the browser context (where WhatsApp Web is running), and that script simply failed. Think of it like this: whatsapp-web.js is trying to tell the WhatsApp Web page, "Hey, click this button," or "Hey, type this message," by injecting and running small pieces of JavaScript directly into the page. The ExecutionContext is precisely the environment in the browser where these little commands get processed. So, when it fails, it's a direct indication that whatever internal script whatsapp-web.js sent to the browser couldn't be executed successfully by WhatsApp Web itself. The b part, while seemingly random, is typically just a minified, internal function name from WhatsApp Web's own JavaScript code. It's a placeholder, a symptom, rather than the root cause itself. The core of the problem lies in the evaluation failure, not the specific letter b. This points to a deeper disconnect or incompatibility between the commands whatsapp-web.js is sending and what WhatsApp Web is expecting or capable of processing at that moment. Understanding this distinction is the first step towards effectively troubleshooting and resolving the issue, as it shifts our focus from the seemingly random b to the underlying mechanisms of browser interaction and script execution.

Understanding ExecutionContext and Puppeteer

To truly grasp this Evaluation failed error, we need to understand the relationship between whatsapp-web.js, puppeteer, and the browser's ExecutionContext. Puppeteer is essentially a high-level API to control Chrome or Chromium over the DevTools Protocol. It allows you to automate browser actions like navigating to pages, taking screenshots, generating PDFs, and crucially for whatsapp-web.js, interacting with elements and executing JavaScript within the page. whatsapp-web.js cleverly leverages puppeteer to automate all the clicks, scrolls, and data entries required to mimic a human user interacting with WhatsApp Web. When you call a function like client.sendMessage(), whatsapp-web.js doesn't directly send an API request to WhatsApp's servers (because there isn't a public, official API for that). Instead, it instructs puppeteer to open WhatsApp Web, log in (or load a session), and then find the chat window, type the message, and click the send button – all by injecting small, targeted JavaScript snippets into WhatsApp Web's browser context. The ExecutionContext is the isolated JavaScript environment specific to a given webpage or frame within the browser where these injected scripts run. When an Evaluation failed error occurs here, it means one of those injected scripts, critical for the sendMessage process, hit a snag. This could be due to a change in WhatsApp Web's DOM structure (e.g., the send button's ID changed), a timing issue where an element wasn't ready when the script tried to interact with it, or even a more fundamental problem with the JavaScript environment itself. This intricate dance between whatsapp-web.js, puppeteer, and the browser's JavaScript engine makes debugging challenging, as the error surfaces deep within the browser's internal workings, often without a clear, human-readable explanation of the precise JavaScript fault.

Common Triggers for This Error

So, what actually triggers this Evaluation failed nightmare? From experience, guys, it usually boils down to a few common culprits. The most frequent reason is changes in the WhatsApp Web UI. WhatsApp is constantly updating its interface, and these changes can break the selectors or JavaScript logic that whatsapp-web.js uses to find elements or perform actions. Imagine whatsapp-web.js is looking for a button with ID "send-msg-btn", but after an update, WhatsApp Web renames it to "chat-submit-button". Boom! The script whatsapp-web.js tries to inject to click that button will fail to find it, leading to an Evaluation failed error. Another big one is timing issues. Sometimes, the element whatsapp-web.js is trying to interact with simply hasn't loaded yet, or it's temporarily hidden. While whatsapp-web.js has some internal waits, complex or slow-loading WhatsApp Web pages can still lead to race conditions. Incorrect puppeteer configurations or arguments can also play a role, potentially messing with the browser's stability or its ability to execute scripts. Outdated whatsapp-web.js or puppeteer versions, especially if they're significantly behind the current WhatsApp Web version, are also prime suspects. Think of it like an old translation guide trying to understand a new language – it just won't work perfectly. Lastly, network issues, slow internet, or WhatsApp Web itself having temporary glitches can sometimes manifest as these evaluation failures, as the browser environment might not be stable enough for the scripts to run correctly. Pinpointing the exact cause often requires a bit of detective work, but knowing these common triggers gives us a strong starting point for our investigation.

Diagnosing and Troubleshooting sendMessage Issues: Let's Get Our Hands Dirty!

Alright, it's time to roll up our sleeves and tackle this Evaluation failed error head-on. The goal here is to methodically identify why your client.sendMessage function is failing. This isn't just about throwing solutions at the wall; it's about understanding the why behind the problem, which will not only fix your current issue but also make you a more robust whatsapp-web.js developer. Remember, guys, automation often feels like magic until it breaks, and then it feels like a puzzle. But don't despair, because with the right approach, we can solve this puzzle together. The key is to be systematic, check every potential point of failure, and gather as much information as possible. Given that the Evaluation failed error points directly to an issue within the browser's execution context, our troubleshooting efforts must focus heavily on the environment where WhatsApp Web operates and how whatsapp-web.js interacts with it. This involves scrutinizing your setup, understanding compatibility nuances, and employing smart debugging techniques. We'll examine your whatsapp-web.js and Puppeteer configuration, delve into the crucial aspect of WhatsApp Web version compatibility, meticulously review your code for any subtle missteps, and finally, equip you with advanced debugging strategies to peel back the layers of this frustrating error. Let's make sure your sendMessage function is back to sending those important messages without a hitch!

Checking Your whatsapp-web.js and Puppeteer Setup

First things first, let's scrutinize your setup. Your configuration snippet shows you're using headless: false and explicitly setting executablePath to Chrome. This is actually a huge advantage for debugging!.

  • Executable Path: Double-check that 'C:\Program Files\Google\Chrome\Application\chrome.exe' is the correct and exact path to your Chrome executable. Even a tiny typo can prevent puppeteer from launching the browser. Sometimes, Chrome updates can change paths, or you might have multiple installations. Make sure it's spot on. If puppeteer can't find Chrome, it won't even start, or it might try to download Chromium, leading to unexpected behavior. Test launching Chrome from that path manually to confirm its validity.
  • headless: false: Since you're using headless: false, when the error occurs, what do you see in the browser window? Does WhatsApp Web load completely? Is your account logged in? Does it look normal, or are there any unusual pop-ups, error messages on the WhatsApp Web page itself, or visual glitches? Observe carefully what happens right before the Evaluation failed error pops up. This visual feedback is invaluable. If WhatsApp Web isn't fully loading or looks broken, that's your first clue.
  • Puppeteer args: You have args: sessionArgs. What's inside sessionArgs? Some puppeteer arguments can cause issues. For instance, sometimes whatsapp-web.js requires specific arguments like --no-sandbox (especially in Docker environments), --disable-setuid-sandbox, or --disable-gpu to function correctly across different OS. While your issue seems to be more about sendMessage failing after the browser launches, conflicting or missing arguments could subtly destabilize the browser context, leading to evaluation failures. It's worth testing with a minimal args array just to rule out any custom flags you might be passing.
  • Node.js Version: You're using Node.js v22.18.0. While whatsapp-web.js generally tries to be compatible, sometimes very new Node.js versions can have subtle incompatibilities with older puppeteer or other dependencies, especially if puppeteer itself isn't explicitly pinned to a version that's compatible with Node 22. It might be worth trying a slightly older, established Node.js LTS (Long Term Support) version, like v18.x or v20.x, just to rule out any bleeding-edge compatibility issues, though this is often a less likely cause unless other components are very old.
  • Dependency Versions: You're on whatsapp-web.js ^1.34.1. What about puppeteer? While whatsapp-web.js pulls in puppeteer as a dependency, sometimes conflicts arise. Ensure you don't have an older puppeteer version explicitly installed or cached that might override the one required by whatsapp-web.js. A fresh npm install after deleting node_modules and package-lock.json can sometimes resolve hidden dependency conflicts, ensuring you get the correct, compatible puppeteer version. Also, check the whatsapp-web.js GitHub issues or README for any specific puppeteer version recommendations. A mismatch here is a surprisingly common root cause of these deeper execution failures, as the core interaction mechanisms rely heavily on the underlying puppeteer functionality being precisely aligned with the whatsapp-web.js commands.

The Role of WhatsApp Web Version Compatibility

Now, this is arguably the most critical factor when it comes to Evaluation failed errors with whatsapp-web.js: WhatsApp Web version compatibility. WhatsApp Web is a living, breathing application that updates frequently. These updates often change the underlying HTML structure, CSS selectors, and JavaScript functions that whatsapp-web.js relies on to interact with the page. Your WhatsApp Web Version is 2.3000.1028340218. whatsapp-web.js needs to be constantly updated by its maintainers to adapt to these changes. If your whatsapp-web.js library version (^1.34.1) is out of sync with a recent WhatsApp Web update, those injected JavaScript commands that trigger sendMessage will fail because the elements it's trying to interact with simply aren't there anymore, or they've changed their IDs/classes. This is often why a sendMessage function that worked perfectly last week suddenly throws Evaluation failed errors today.

  • Check whatsapp-web.js GitHub Issues: This is your first port of call, guys. Go to the whatsapp-web.js GitHub repository and check the "Issues" and "Discussions" sections. Search for Evaluation failed, sendMessage, or your specific WhatsApp Web version. It's highly likely that if WhatsApp Web just updated and broke something, other users will be experiencing the exact same issue and reporting it. You might find an existing issue explaining the problem, a temporary workaround, or even an announcement from the maintainers about a pending fix. This is often where you'll find the most up-to-date information on known incompatibilities.
  • Downgrade/Upgrade whatsapp-web.js: If a newer version of whatsapp-web.js has been released specifically to address a WhatsApp Web update, then upgrading might be the solution. Conversely, if the latest WhatsApp Web update broke things and whatsapp-web.js hasn't caught up, sometimes downgrading your whatsapp-web.js to a previous version that was known to work with an older WhatsApp Web version (if you can somehow force WhatsApp Web to an older state, which is hard) or simply waiting for the whatsapp-web.js team to release a patch is your only option. Realistically, waiting for a library update is often the most practical solution here, as WhatsApp Web often forces updates on its users.
  • Observe WhatsApp Web Directly: With headless: false, manually try to send a message to the same contact that your bot is trying to message. Does it work? Does the UI look different? Are there any new pop-ups or warnings? Sometimes, WhatsApp Web itself might be experiencing temporary issues or asking for CAPTCHAs, which would naturally lead to Evaluation failed errors for the bot.

Code Review: Are You Doing It Right?

Let's take a quick look at your provided code snippet. The structure for initializing the client and sending a message after ready is generally correct and follows common patterns. You're using client.once("ready", async () => { ... }); which is good practice to ensure the client is fully initialized before attempting actions. You then correctly use await client.sendMessage(...). The issue is unlikely to be a fundamental flaw in how you're calling sendMessage itself, given your snippet is quite standard.

  • Contact ID: You've masked the contact ID with "##". While the Evaluation failed error typically occurs before the message is even attempted to be sent to a specific contact (it's more about the internal mechanism of sending), it's crucial to ensure your target contact ID is in the correct format. It should be a string like '1234567890@c.us' for a regular chat or '1234567890-123456@g.us' for a group chat. An incorrectly formatted ID might lead to a different error, but it's always good to confirm this detail. Make sure the ID is valid and accessible by the WhatsApp account logged in through your bot.
  • Message Content: While extremely rare to cause an Evaluation failed error, ensure your message content isn't excessively long or contains unusual characters that might trip up WhatsApp Web's input fields. Again, this is a long shot, but ruling out the obvious is part of thorough debugging.

Given the nature of Evaluation failed, the problem usually lies deeper than the simple syntax of your sendMessage call; it points more towards the environment and compatibility. However, a quick sanity check of the call parameters is never a bad idea.

Advanced Debugging Techniques

When the simpler checks don't yield answers, it's time to pull out some advanced debugging tricks. These methods require a bit more effort but can provide invaluable insights into exactly what is failing inside the browser.

  • Browser Console Inspection (with headless: false): Since you're running headless: false, you have a live browser window! When the Evaluation failed error occurs in your Node.js console, immediately switch to the Chrome window your bot is controlling. Open the Developer Tools (usually by pressing F12 or Ctrl+Shift+I on Windows/Linux, Cmd+Option+I on macOS). Go to the "Console" tab. Are there any errors or warnings shown there? The Evaluation failed you see in Node.js is often a wrapper around a more specific JavaScript error that happened inside WhatsApp Web. This internal browser console error can give you the exact line number and context of the JavaScript failure within WhatsApp Web's own code, which can be incredibly helpful when searching for similar issues on GitHub or understanding the root cause. Also, check the "Network" tab for any failed requests or unusually long loading times during the sendMessage operation.
  • More Verbose Puppeteer Logging: puppeteer itself can often be configured for more verbose logging, although whatsapp-web.js might abstract some of this away. However, if you can access puppeteer's internal events or logs (sometimes by adding specific environment variables or DEBUG flags for puppeteer itself), you might get more context about the browser's state or what puppeteer was trying to do right before the failure. Check puppeteer's documentation for debug flags. While not always directly applicable when using whatsapp-web.js as an abstraction, understanding puppeteer's own error reporting can sometimes shed light.
  • Stepping Through with Node.js Debugger: If you suspect a timing issue or want to confirm your code execution flow, you can use Node.js's built-in debugger. Add debugger; statements in your code before and around the client.sendMessage call. Run your Node.js script with node --inspect index.js (or whatever your main file is). Open chrome://inspect in your Chrome browser, click "Open dedicated DevTools for Node.js," and step through your code. This allows you to inspect variables, confirm that client is indeed ready, and see if any preceding steps are implicitly failing before sendMessage is even attempted. This is a powerful way to understand the runtime behavior of your application.
  • Isolated Testing: Try to simplify your code to the bare minimum required to reproduce the sendMessage error. Remove any custom logic, extra event listeners, or other bot functionalities. If a minimal script also fails, it strongly points to an environment or compatibility issue. If the minimal script works, then the issue is somewhere in your additional code. This helps narrow down the problem space significantly.

Best Practices for Robust whatsapp-web.js Development: Future-Proofing Your Bots!

Successfully resolving the Evaluation failed error is just one step, guys. To build truly robust and resilient whatsapp-web.js bots, we need to adopt some best practices that will help prevent these kinds of frustrating issues in the future. Think of it as investing in the long-term health of your automation projects. By following these guidelines, you'll not only spend less time troubleshooting but also create a more stable and reliable WhatsApp bot that can weather the inevitable storms of updates and environmental changes. These practices go beyond mere bug fixes; they're about architecting your solution for longevity, maintainability, and consistent performance, ensuring that your automated messaging continues to function seamlessly even as WhatsApp Web evolves. It’s about building a foundation that minimizes disruption and maximizes uptime, providing continuous value to your users or business operations without constant manual intervention.

Keeping Dependencies Updated (Wisely)

I know, I know, constant updates can be a pain, but with a library like whatsapp-web.js that depends on a third-party UI (WhatsApp Web) over which we have no control, staying updated is paramount. However, there's a trick: don't just npm update blindly every single day. Instead, adopt a strategy:

  • Monitor whatsapp-web.js Releases: Regularly check the whatsapp-web.js GitHub repository for new releases. The changelog often explicitly mentions fixes for WhatsApp Web UI changes or compatibility improvements. This is a great indicator of when you should update.
  • Test Updates in Staging: Never deploy a whatsapp-web.js update directly to production. Always test it thoroughly in a staging or development environment first. What works on your machine might break on the server, especially with different browser or Node.js versions.
  • Pin Major Versions: In your package.json, consider using exact versions or pinning to minor versions (e.g., "whatsapp-web.js": "^1.34.1" might become "whatsapp-web.js": "1.34.1" or "~1.34.1") once you find a stable combination with your current WhatsApp Web version. While ^ allows for minor and patch updates, sometimes a minor update introduces breaking changes due to rapid adaptation to WhatsApp Web. This allows you more control over when you introduce new library versions.
  • Puppeteer Alignment: Remember that whatsapp-web.js relies heavily on puppeteer. Ensure that the puppeteer version being used (either explicitly installed or pulled in by whatsapp-web.js) is compatible. Sometimes, whatsapp-web.js might require a specific puppeteer version to function optimally, so check their documentation or issues for any such recommendations.

Handling Sessions and Authentication

Your choice of LocalAuth is straightforward, but session management is super important for bot stability.

  • Session Corruption: LocalAuth stores session data in a local file system. If your application crashes abruptly or is terminated without client.destroy() being called, the session file can get corrupted, leading to auth_failure or difficulty in restarting. Always try to implement graceful shutdown procedures for your Node.js application.
  • client.destroy() and client.initialize(): Always call client.destroy() when you're done with the client or before restarting it, and then client.initialize() to start a fresh connection. This helps manage resources and prevent stale sessions.
  • MultiDeviceAuthStrategy: For more advanced scenarios or if you're experiencing frequent session issues, whatsapp-web.js also offers MultiDeviceAuthStrategy. While LocalAuth is simpler, MultiDeviceAuthStrategy can sometimes be more resilient, especially in environments where session files might be tricky to manage or if you want better support for multi-device login scenarios. It's worth researching if LocalAuth proves consistently problematic for your specific deployment needs.
  • Regular Re-authentication: Although not always necessary, consider a mechanism to periodically check if the client is still authenticated (e.g., client.isAuthenticated()) and trigger a re-login or QR code scan if it drops, rather than waiting for an error during a sendMessage call.

Graceful Error Handling

Errors are inevitable in software, especially when dealing with external services. How you handle them defines the robustness of your bot.

  • try...catch Blocks: Wrap your client.sendMessage() calls (and other critical actions) in try...catch blocks. This prevents a single message failure from crashing your entire application. Inside the catch block, you can log the error, attempt a retry, or notify an administrator.

    try {
      await client.sendMessage(contactId, messageContent);
      console.log('Message sent successfully!');
    } catch (error) {
      console.error('Failed to send message:', error);
      // Implement retry logic or alert system
    }
    
  • Event Listeners: Utilize whatsapp-web.js's extensive event listeners:

    • client.on('auth_failure', (msg) => console.error('Authentication failed:', msg)); – Crucial for detecting session problems.
    • client.on('disconnected', (reason) => console.error('Client disconnected:', reason)); – Helps understand why your bot went offline.
    • client.on('qr', (qr) => console.log('New QR code:', qr)); – Essential if you need to re-scan often.
  • Logging: Implement comprehensive logging. Use a logging library (like Winston or Pino) to record not just errors, but also warnings, successful actions, and key events. This makes debugging much easier when problems arise, allowing you to trace the bot's behavior over time.

  • Retry Mechanisms: For transient errors (like network issues or temporary WhatsApp Web glitches), implement a simple retry mechanism with exponential backoff. Don't hammer the service repeatedly; wait a bit longer between retries.

By incorporating these best practices, you'll significantly increase the resilience and reliability of your whatsapp-web.js bot, allowing you to focus more on building awesome features and less on constant firefighting.

Community Support and Resources: You're Not Alone, Guys!

When you're stuck on a tricky issue like Evaluation failed: b at ExecutionContext._ExecutionContext_evaluate, remember that you're definitely not alone! The whatsapp-web.js community is vibrant and often facing similar challenges, especially given how frequently WhatsApp Web updates. Leveraging this community and available resources can save you hours of head-scratching and frustration. It's all about knowing where to look and how to ask for help effectively, and equally important, how to contribute back once you've found a solution. The beauty of open-source projects is the collective knowledge and experience of developers worldwide, which becomes a powerful tool in troubleshooting complex problems that might seem insurmountable on your own. Engaging with this network can not only resolve your immediate issues but also broaden your understanding of the library and its ecosystem, turning individual hurdles into shared learning opportunities.

  • whatsapp-web.js GitHub Issues/Discussions: As mentioned earlier, this is your prime resource. Before creating a new issue, search existing ones thoroughly. Someone else might have already reported the exact Evaluation failed error with the same whatsapp-web.js and WhatsApp Web versions. If you find a similar issue, contribute to that discussion instead of creating a duplicate. If no one has reported it, create a detailed issue with your setup, code, and the full error log. The more information you provide, the easier it is for maintainers and other community members to help you. These discussion forums are often teeming with valuable workarounds, temporary fixes, and official updates from the library's core contributors.
  • Stack Overflow: Search Stack Overflow for whatsapp-web.js, puppeteer, and specific error messages like Evaluation failed. You might find solutions or insights related to puppeteer's behavior that apply to whatsapp-web.js, even if the exact library isn't mentioned. It's a vast repository of solved programming challenges.
  • Discord/Telegram Groups: Check the whatsapp-web.js GitHub repository for any official or community-run Discord or Telegram channels. Real-time chat with other developers can be incredibly fast for getting help or sharing quick tips. Sometimes, a casual conversation can lead to a breakthrough that formal issue reporting might miss.
  • Contribute Back: Once you've found a solution or a workaround to your Evaluation failed problem, consider sharing it back with the community! Update the GitHub issue you commented on, or even submit a pull request if you've found a way to improve the library's documentation or code. Helping others not only strengthens the community but also solidifies your own understanding of the problem and its solution. Your insights can be the lifeline for the next developer encountering this same frustrating error.

Wrapping It Up: Your Path to sendMessage Success

Whew! We've covered a lot of ground, haven't we, guys? Tackling the Evaluation failed: b at ExecutionContext._ExecutionContext_evaluate error when trying to use client.sendMessage in whatsapp-web.js can feel like hitting a brick wall. But as we've seen, it's a conquerable challenge, often boiling down to a methodical process of elimination. The core takeaway here is that this specific error usually points to a mismatch or instability in the delicate dance between your whatsapp-web.js library, the underlying puppeteer browser automation, and the ever-changing landscape of WhatsApp Web itself. It’s not necessarily a flaw in your core logic but rather a compatibility hiccup or an environmental snag that prevents whatsapp-web.js from executing its crucial browser-side scripts. By systematically checking your dependency versions, scrutinizing your puppeteer setup, staying vigilant about WhatsApp Web updates, and leveraging detailed browser console insights, you can pinpoint the root cause.

Remember, the journey of building reliable bots isn't always smooth sailing, but with persistence, a little detective work, and the right debugging tools, you can overcome these hurdles. Embrace headless: false for visual debugging, consult the whatsapp-web.js community, and always aim for robust error handling in your code. Don't let this Evaluation failed error deter you from building incredible automation solutions. Now that you're armed with this knowledge, go forth and make your sendMessage functions sing! Happy bot building, and here's to many successful messages ahead!