How to Fix Error Squiggles Not Showing in VS Code

Error squiggles in Visual Studio Code help developers identify syntax errors, warnings, missing imports, type mismatches, and other coding issues in real time. These colored underlines are powered by language servers, extensions, linters, and IntelliSense features.

However, some users notice that error squiggles suddenly stop appearing in VS Code, even though the code contains obvious mistakes. This can make debugging difficult and reduce productivity significantly.

The issue is usually caused by disabled validation settings, broken extensions, language server problems, corrupted workspace settings, or extension conflicts. In this guide, we’ll walk you through effective methods to fix error squiggles not showing in VS Code on Windows 11.

How to Fix Error Squiggles Not Showing in VS Code

Before applying the fixes below, restart Visual Studio Code once and reopen the affected project. Then follow the methods below in order.

1. Verify the Correct Language Mode

VS Code may not detect the correct programming language.

1. Open the affected file in Visual Studio Code.
2. Check the language mode in the bottom-right corner.
3. If incorrect, click it and select the proper language manually.

Without the correct language mode, syntax validation may not work.

2. Enable Error Validation Settings

Validation may be disabled in VS Code settings.

1. Press Ctrl + Shift + P.
2. Search for: Preferences: Open Settings (JSON)
3. Verify that language validation is enabled.

For example, for JavaScript and TypeScript:

"javascript.validate.enable": true,
"typescript.validate.enable": true

This restores built-in error checking.

3. Restart the Language Server

Language servers are responsible for diagnostics and squiggles.

1. Press Ctrl + Shift + P.
2. Run commands such as:
   • TypeScript: Restart TS Server
   • Python: Restart Language Server
   • Relevant restart command for your language extension

This refreshes IntelliSense and diagnostics.

4. Check Installed Extensions

Missing or broken extensions can disable error highlighting.

1. Open the Extensions panel (Ctrl + Shift + X).
2. Verify the required language extension is installed.

Common examples include:

• Python Extension for Visual Studio Code
• ESLint
• Pylance

Update or reinstall the extension if necessary.

5. Enable Problems Panel Diagnostics

The Problems system may be disabled or malfunctioning.

1. Press: Ctrl + Shift + M
2. Check whether errors appear in the Problems panel.

If errors appear there but not in the editor, the issue is usually visual or theme-related.

6. Disable Conflicting Extensions

Some extensions interfere with diagnostics.

1. Disable recently installed extensions temporarily.
2. Restart VS Code.
3. Check whether squiggles return.

Theme packs, AI tools, or formatter extensions sometimes cause conflicts.

7. Check Workspace Settings

Project-level settings may override global diagnostics.

1. Open the workspace .vscode/settings.json file.
2. Look for settings disabling validation or linting.
3. Remove conflicting entries if necessary.

Workspace settings can override global behavior.

8. Re-enable Linting Tools

If you use linters, ensure they are active.

For example, for ESLint:

1. Open Settings.
2. Search for: eslint.enable
3. Ensure it is enabled.

Also verify required dependencies are installed in the project.

9. Reset VS Code Settings

Corrupted settings can break diagnostics.

1. Press Ctrl + Shift + P.
2. Open: Preferences: Open Settings (JSON)
3. Backup and reset suspicious settings.

You can also temporarily rename the VS Code user settings folder to test defaults.

10. Reinstall VS Code

If nothing works, reinstalling VS Code may help.

1. Uninstall Visual Studio Code.
2. Delete leftover configuration folders if needed.
3. Download the latest version from the official website.
4. Reinstall the editor and extensions.

A clean installation often resolves persistent editor issues.

Conclusion

Error squiggles not showing in Visual Studio Code is usually caused by disabled validation settings, broken language servers, or extension conflicts. By following the methods outlined in this guide, you can restore real-time error highlighting and diagnostics.

From restarting language servers to checking extensions and resetting settings, these solutions cover both simple and advanced troubleshooting methods. Once fixed, VS Code should display syntax and code errors normally again.