Fix 'getGlobalClassNames Is Not A Function' Error

by RICHARD 50 views

Introduction

Hey everyone! We're going to dive deep into a tricky issue that many SharePoint users encountered after the July 2025 updates (specifically, KB5002753 and KB5002754): the dreaded "getGlobalClassNames is not a function" error. If you're seeing this error after updating your SharePoint 2019 environment, you're definitely not alone. This article aims to break down what's causing this issue, why it's happening, and, most importantly, how to fix it. We'll cover everything from the technical background to practical solutions, ensuring you can get your SharePoint site back up and running smoothly. We'll also explore the implications of this error in the context of React, Reactjs, and Fluent UI, which are commonly used in SharePoint customizations. So, let's get started and tackle this head-on!

Understanding the "getGlobalClassNames is not a Function" Error

When you encounter the "getGlobalClassNames is not a function" error, it's crucial to understand what it actually means. This error typically arises in the context of JavaScript applications, especially those utilizing frameworks and libraries like React, Reactjs, and Fluent UI (formerly known as Office UI Fabric). The getGlobalClassNames function is often part of a styling solution or component library that helps manage and apply CSS classes to elements within the user interface. In simpler terms, it's a tool that helps developers style their applications consistently and efficiently. Now, when you see this error, it indicates that your application is trying to call a function named getGlobalClassNames, but for some reason, this function is either not defined, not accessible in the current scope, or has been removed or renamed. The reasons behind this can vary, ranging from incorrect imports, version mismatches, or issues during the update process. Specifically, within SharePoint environments, this error often surfaces due to customizations that rely on older versions of UI libraries or components that are not fully compatible with the latest updates. To effectively address this, we need to delve into the specific context of the error, examining the code that's triggering it and the libraries involved. This understanding forms the foundation for troubleshooting and implementing the correct fix.

The SharePoint 2019 July 2025 Update and Its Impact

The July 2025 updates for SharePoint 2019 (KB5002753 and KB5002754) brought a mix of improvements, security patches, and, unfortunately, some unforeseen issues. As with any major update, these patches aim to enhance the platform's stability, performance, and security. However, the complex nature of SharePoint, especially in customized environments, means that updates can sometimes introduce compatibility problems. In this particular case, the "getGlobalClassNames is not a function" error became a prevalent issue after applying these updates, particularly for environments that were previously running version 16.0.10417.20010 (May 2025). The underlying reason often stems from changes in the underlying JavaScript libraries or components that SharePoint uses, especially those related to UI rendering and styling. When custom solutions or web parts rely on specific versions of these libraries, an update that changes or removes certain functions can break the existing functionality. This is where the getGlobalClassNames error comes into play. If your custom code is trying to use this function, and the updated SharePoint version either doesn't include it or has modified its implementation, you'll encounter this error. Therefore, it's essential to understand the changes introduced by the update and how they might affect your custom components. This involves carefully reviewing the update documentation, analyzing the error logs, and potentially debugging your code to identify the root cause. By understanding the update's impact, you can then devise a targeted solution to resolve the issue.

Root Causes of the "getGlobalClassNames" Issue in SharePoint

To effectively fix the "getGlobalClassNames is not a function" error in your SharePoint 2019 environment, it's essential to understand the common root causes behind it. Several factors can contribute to this issue, often stemming from the interplay between SharePoint updates and custom solutions. Here are some of the most frequent culprits:

  1. Version Mismatches in UI Libraries: This is a primary cause. Custom web parts or solutions might be using specific versions of UI libraries like Fluent UI (formerly Office UI Fabric) or React. The SharePoint update might have upgraded these libraries, and if your custom code isn't compatible with the new versions, you might encounter the error. The getGlobalClassNames function could have been removed, renamed, or its signature might have changed.
  2. Incompatible Customizations: Customizations, such as web parts, application customizers, or field customizers, often rely on JavaScript and CSS. If these customizations use the getGlobalClassNames function directly or indirectly through a component library, they could break after the update if the function is no longer available or behaves differently.
  3. Incorrect Import Statements: Sometimes, the error can arise from incorrect or outdated import statements in your JavaScript code. If you're trying to import getGlobalClassNames from a library or module where it doesn't exist or is no longer exported, you'll get this error.
  4. Cache Issues: Browser or SharePoint cache can sometimes lead to unexpected behavior after an update. Old versions of JavaScript files might be cached, causing conflicts with the updated SharePoint environment. Clearing the cache can often resolve such issues.
  5. Deployment Problems: In some cases, the update process itself might have encountered issues, leading to incomplete or corrupted files. This could result in missing functions or libraries, including getGlobalClassNames.
  6. Dependencies: SharePoint solutions often have dependencies on other libraries and components. If one of these dependencies is not correctly updated or is incompatible with the new SharePoint version, it can trigger the error.

Identifying the specific root cause in your environment requires careful investigation, including examining error logs, reviewing custom code, and understanding the changes introduced by the SharePoint update. Once you pinpoint the cause, you can apply the appropriate solution.

Troubleshooting Steps to Resolve the Error

When faced with the "getGlobalClassNames is not a function" error in SharePoint 2019, a systematic troubleshooting approach is crucial. Here’s a step-by-step guide to help you identify and resolve the issue:

  1. Examine the Error Context: Start by pinpointing where the error occurs. Check the browser's developer console for the full error message and stack trace. This will give you clues about the specific file and line of code where the error is being thrown. This is your starting point for understanding which component or script is causing the issue.
  2. Review Custom Code: If the error points to a custom web part, application customizer, or other customization, carefully review the JavaScript and CSS code. Look for instances where getGlobalClassNames is being called or where UI libraries like Fluent UI are being used. Pay close attention to import statements and version numbers.
  3. Check Library Versions: Verify the versions of any UI libraries your custom code is using, such as Fluent UI or React. Ensure that these versions are compatible with the SharePoint 2019 July 2025 updates (KB5002753, KB5002754). If there's a mismatch, you might need to update your code or the library version.
  4. Inspect Import Statements: Double-check your import statements to ensure that you're correctly importing getGlobalClassNames or any related functions. Make sure the path to the module or library is accurate and that the function is actually exported.
  5. Clear Browser and SharePoint Cache: Cached files can sometimes cause conflicts after an update. Clear your browser's cache and cookies, and also clear the SharePoint cache. This ensures that you're loading the latest versions of the JavaScript files.
  6. Test in Different Browsers: The issue might be browser-specific. Try reproducing the error in different browsers (e.g., Chrome, Firefox, Edge) to see if the problem persists. This can help you rule out browser-related caching or compatibility issues.
  7. Review SharePoint Logs: Check the SharePoint ULS logs and the Windows Event Viewer for any additional error messages or warnings. These logs can provide more detailed information about the underlying issue.
  8. Disable Customizations: If you suspect a specific customization is causing the error, try temporarily disabling it to see if the issue resolves. This can help you isolate the problem.
  9. Consult Documentation and Forums: Refer to the official documentation for the UI libraries you're using and search online forums (like the Microsoft Tech Community or Stack Overflow) for similar issues. Other developers might have encountered and resolved the same problem.

By following these troubleshooting steps systematically, you'll be able to narrow down the root cause of the "getGlobalClassNames is not a function" error and implement the appropriate fix.

Practical Solutions and Code Examples

Once you've identified the root cause of the "getGlobalClassNames is not a function" error, it's time to implement a solution. Here are some practical approaches and code examples to help you resolve the issue:

  1. Updating UI Library Versions:

    If the error is due to a version mismatch in UI libraries like Fluent UI, the first step is to update your project to use a compatible version. This might involve:

    • Updating the library package in your project's package.json file.
    • Running npm install or yarn install to install the updated packages.
    • Modifying your code to use the new API if there are breaking changes.

    For example, if you're using Fluent UI React, you might update your package.json like this:

    {
  "dependencies": {
    "@fluentui/react": "^8.0.0" // Replace with the compatible version
  }
}

    Then, run npm install to apply the changes. Remember to test your code thoroughly after updating libraries to ensure everything works as expected.

  2. Refactoring Code to Avoid Deprecated Functions:

    If getGlobalClassNames is deprecated or removed in the updated library version, you'll need to refactor your code to use the new recommended approach. This might involve:

    • Replacing getGlobalClassNames with alternative styling solutions provided by the library.
    • Using CSS-in-JS techniques or other styling methodologies.

    For instance, if Fluent UI has introduced a new styling API, you would adapt your code to use it. Refer to the library's documentation for guidance on the recommended approach.

  3. Correcting Import Statements:

    Ensure that your import statements are correct and that you're importing getGlobalClassNames from the correct module or library. If the function has been moved or renamed, update your import statements accordingly. For example:

    // Old import
// import { getGlobalClassNames } from 'old-library';

// New import (example)
import { newStylingFunction as getGlobalClassNames } from 'new-library';

  4. Using Conditional Logic for Compatibility:

    In some cases, you might need to maintain compatibility with older SharePoint versions while also supporting the updated version. You can use conditional logic to use different code paths based on the SharePoint version. This involves checking the SharePoint version at runtime and using the appropriate styling approach.

  5. Creating Custom Styling Solutions:

    If the UI library doesn't provide a direct replacement for getGlobalClassNames, you might need to create your own styling solution. This could involve writing your own function to generate CSS class names or using a CSS-in-JS library. Be sure to follow best practices for styling in React or your chosen framework.

By implementing these practical solutions and adapting your code as needed, you can effectively resolve the "getGlobalClassNames is not a function" error and ensure your SharePoint customizations work smoothly after the update.

Preventing Future Issues: Best Practices

To minimize the risk of encountering issues like the "getGlobalClassNames is not a function" error after future SharePoint updates, it's crucial to adopt some best practices for developing and maintaining custom solutions. Here are some key strategies:

  1. Use Semantic Versioning (SemVer):

    When managing dependencies in your project (e.g., UI libraries, JavaScript frameworks), use semantic versioning (SemVer). SemVer helps you specify compatible versions of libraries in your package.json file. For example:

    • ^8.0.0: Allows updates within the same major version (e.g., 8.x.x).
    • ~8.0.0: Allows updates within the same minor version (e.g., 8.0.x).

    Using SemVer ensures that you receive bug fixes and new features without introducing breaking changes.

  2. Regularly Update Dependencies:

    Keep your project's dependencies up to date. Regularly check for new versions of UI libraries, frameworks, and other components. Staying current can help you avoid compatibility issues and take advantage of new features and performance improvements.

  3. Thoroughly Test Updates in a Test Environment:

    Before deploying updates to your production SharePoint environment, always test them thoroughly in a test or staging environment. This allows you to identify and resolve any compatibility issues or errors without impacting your users.

  4. Follow Official Documentation and Best Practices:

    Adhere to the official documentation and best practices for the UI libraries and frameworks you're using. This ensures that your code is compatible with the latest versions and avoids using deprecated or unsupported features.

  5. Implement Proper Error Handling:

    Incorporate robust error handling in your code. Use try-catch blocks to catch exceptions and log errors. This makes it easier to identify and diagnose issues when they occur. For example:

    try {
  // Code that might throw an error
  const result = getGlobalClassNames();
  // ...
} catch (error) {
  console.error('Error:', error);
}

  6. Use a Consistent Styling Approach:

    Adopt a consistent styling approach in your project, such as CSS-in-JS or a well-defined CSS architecture. This makes your code more maintainable and reduces the risk of styling conflicts after updates.

  7. Monitor SharePoint Announcements:

    Stay informed about upcoming SharePoint updates and announcements. Microsoft often provides information about changes that might affect custom solutions. This allows you to proactively address potential compatibility issues.

By implementing these best practices, you can create more robust and maintainable SharePoint customizations, reducing the likelihood of encountering errors like "getGlobalClassNames is not a function" in the future. This proactive approach ensures a smoother SharePoint experience for both developers and users.

Conclusion

The "getGlobalClassNames is not a function" error that surfaced after the July 2025 SharePoint 2019 updates can be a real headache, but armed with the right knowledge and troubleshooting steps, you can conquer it. We've journeyed through understanding the error, its root causes, practical solutions, and proactive measures to prevent future issues. Remember, the key takeaways are to examine your code, verify library versions, correct import statements, and always test updates in a non-production environment first. Embracing best practices in development and staying informed about SharePoint updates will not only resolve this specific issue but also lead to more robust and maintainable SharePoint solutions overall. So, keep coding, keep learning, and keep your SharePoint environments running smoothly!