VS Code stopped showing syntax errors

Question

VS Code stopped showing syntax errors

Vivian 0

My visual studio code stopped showing the red squiggly lines for syntax errors and I have tried every solution that I have googled. I even asked my programming prof what was wrong with my VS code and he didn't know after. I even reinstalled VS Code but the syntax errors still won't show. The settings are correct and there seems to be no problem with the set up so I genuinely have no clue why it's not working.

Is anyone else having this problem? Is there a solution to this? I would very much appreciate any solution that would help fix this.

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Answer 1

Varsha Dundigalla(INFOSYS LIMITED) 4,420 Microsoft External Staff

Thank you for reaching out.

It happens because VS Code relies on a language server (the extension for your language) to analyze files and emit diagnostics; if the server isn’t active for the current workspace, validation is turned off in settings, the server fails to start due to an extension conflict or a bad update, the file is opened with the wrong language mode or outside a proper project folder, or cached workspace settings override validation, those diagnostics never arrive so no red squiggles appear.

Workaround:

• Open the actual project folder (File → Open Folder), not a single file, and ensure the file’s language mode is correct from the status bar.

• Disable nonessential extensions, reload VS Code, then re‑enable only the core language extension; add others back one by one to catch conflicts.

• In Settings, search “validation/diagnostics” and re‑enable language diagnostics (e.g., JavaScript/TypeScript validation, C/C++ error squiggles, Python/Pylance diagnostics).

• Open View → Output and select your language server’s log; if it shows startup errors, reload the window or reinstall the language extension.

• Remove workspace overrides by checking .vscode/settings.json; delete entries that disable validation, then reload the window.

Reference:

Language Server Extension Guide

Please let us know if you require any further assistance, we’re happy to help. If you found this information useful, kindly mark this as "Accept Answer". So that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

Vivian 0 Reputation points

2026-01-06T19:17:14.8433333+00:00

Hi, I tried all of these but it still doesn't work. Are there more possible solutions that I could try?
Varsha Dundigalla(INFOSYS LIMITED) 4,420 Reputation points Microsoft External Staff

2026-01-07T13:41:53.8+00:00

Just to understand this better, are you opening the full project folder in VS Code (File → Open Folder), or opening a single file directly? This helps because the language server usually starts only when a project folder is opened.
Vivian 0 Reputation points

2026-01-07T19:05:46.0966667+00:00

I tried both and it doesn't work.
Varsha Dundigalla(INFOSYS LIMITED) 4,420 Reputation points Microsoft External Staff

2026-01-08T12:16:23.6033333+00:00
Thank you for reaching out.

If red squiggly lines still don’t show, the most common reason is that the language service (language server) is not actually running, so VS Code never receives diagnostics to display. A few additional things to check:

Check if VS Code is in Restricted Mode (Workspace Trust). Look at the bottom status bar. If it says Restricted Mode, trust the folder/workspace and reopen it. In restricted mode, some language extensions won’t fully run, so diagnostics may not appear.

Test with a clean VS Code profile (rules out a corrupted profile/settings sync). Create a new Profile in VS Code (no extra extensions), then install only the one language extension you need (Python/Pylance, C#, C/C++, etc.) and test again. If it works there, the issue is likely caused by a setting/profile or an extension conflict in your main setup.

Find extension conflicts using Extension Bisect. If squiggles appear in a clean profile but not in your normal one, use Extension Bisect to identify which extension is breaking diagnostics.

Check the language server Output log for startup errors. Open View → Output, select your language server (Python/Pylance, C#, C/C++, TypeScript, etc.), and see if it shows errors like “failed to start” or “crashed”. That usually explains why squiggles never show.

If you tell me which language you’re working with (Python / C# / C/C++ / JS/TS).

References:

Workspace Trust / Restricted Mode:

https://code.visualstudio.com/api/extension-guides/workspace-trust

Extension Bisect (find conflicting extensions): https://code.visualstudio.com/blogs/2021/02/16/extension-bisect

Language Server overview (how diagnostics are produced): https://code.visualstudio.com/api/language-extensions/language-server-extension-guide

Settings Sync / Profiles: https://code.visualstudio.com/docs/configure/settings-sync

Please let us know if you require any further assistance, we’re happy to help. If you found this information useful, kindly mark this as "Accept Answer". So that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.
Vivian 0 Reputation points

2026-01-10T19:49:57.86+00:00
Okay so I think the issue is that the language server crashed and it won't restart. I don't know if this relates but my workspace is taking forever to scan and has been stuck on "initializing" for a long time.

This is the output error message:

[Error - 2:38:54 PM] Server initialization failed. Message: write EPIPE Code: -32099 [Error - 2:38:54 PM] cpptools client: couldn't create connection to server. Message: write EPIPE Code: -32099 [Error - 2:38:54 PM] The language server crashed 5 times in the last 3 minutes. It will not be restarted.

I am working with C/C++.

Please let me know what my next steps are.
Varsha Dundigalla(INFOSYS LIMITED) 4,420 Reputation points Microsoft External Staff

2026-01-12T14:50:00.5833333+00:00

Thanks for sharing details.

It might be that the C/C++ language server is getting stuck while starting up and then crashing, especially if the workspace is taking a long time to scan and stays on “initializing”.

Try excluding any large build or generated folders and then reload VS Code. This often reduces the amount of scanning the C/C++ extension has to do during startup.

Also try uninstalling and reinstalling only the C/C++ extension to give the language server a fresh start. This can help if the server binary or its startup state got corrupted.

Please try these steps and share whether the “initializing” state clears and the C/C++ output stops showing the repeated crash message.

Please let us know if you require any further assistance, we’re happy to help. If you found this information useful, kindly mark this as "Accept Answer". So that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.
Vivian 0 Reputation points

2026-01-12T20:45:27.24+00:00

I tried opening up a smaller folder to test and uninstall and reinstall C/C++ extension but it still doesn't show the error squiggly lines. It seems that my VS code is stuck with workspace "initializing" and the language server crash notifications keep showing.
Varsha Dundigalla(INFOSYS LIMITED) 4,420 Reputation points Microsoft External Staff

2026-01-13T04:22:23.7966667+00:00

Thanks for sharing details.

Since the issue still occurs even in a smaller folder and after reinstalling the C/C++ extension, this points to the C/C++ language server itself failing to start on the system rather than a project‑specific problem.

When the language server crashes during startup, VS Code gets stuck in “initializing” and can’t show any error squiggles or IntelliSense. This might happen due to recent updates, permission or security restrictions, or environment‑level changes, even if everything worked earlier.

To understand exactly why this started happening and narrow it down further, it would help to know your VS Code version, C/C++ extension version, OS, and whether this started after an update or system change. Also, confirming if the behavior is the same in a brand‑new empty folder with a single .cpp file would help determine whether this is an environment issue.
Vivian 0 Reputation points

2026-01-14T17:39:32.4033333+00:00

VS Code version: 1.108.0

C/C++ Extension version: 1.3.1

Windows 11 version: 25H2

I can't confirm for sure but I think this problem started happening after a windows update. However, I can confirm that the issue still remains when I open a brand new empty folder with a single .cpp file.
Varsha Dundigalla(INFOSYS LIMITED) 4,420 Reputation points Microsoft External Staff

2026-01-16T11:55:20.5233333+00:00

Thank you for reaching out.
Since the issue still happens in a brand‑new empty folder with a single .cpp file, this shows it isn’t related to your project or workspace. What’s happening is that the C/C++ language server is crashing while starting, which is why VS Code stays stuck on “initializing” and no error squiggly lines appear.

As a next step, try starting VS Code once with elevated permissions and check whether the workspace finishes initializing or if the crash messages continue. Also, opening the C/C++ entry in the Output panel right after VS Code starts can help show where the language server is failing.

Based on what you see there, we can narrow this down further and guide the next steps.
Vivian 0 Reputation points

2026-01-18T04:26:03.5166667+00:00

IT WORKS!!! After running VS code as administrator, the red squiggly syntax errors finally show. Thank you so much for taking your time to help me, I'm very grateful! :)
Varsha Dundigalla(INFOSYS LIMITED) 4,420 Reputation points Microsoft External Staff

2026-01-19T11:46:31.42+00:00

Thank you for your response. We will now proceed with closure of the thread as per your confirmation. If you encounter any further issues, please feel free to raise a new thread.

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VS Code stopped showing syntax errors

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