C# syntax support not working

Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Hi Folks,

New cursor user here. I am a .Net developer and when doing development in the IDE I get intellisense ok. But I get nothing about syntax errors. No red lines and nothing the problems window. I tried some hacks/workarounds that I found on StackOverflow and chatting with Copilot. But it is still not work. Can I please get some assistance on this? Thank you

Steps to Reproduce

Open root folder of the location where the solution is. Open class file. Type in x = foo;

Expected Behavior

red squiggly line under code and line number identified in problem window.

Operating System

Windows 10/11

Current Cursor Version (Menu → About Cursor → Copy)

Version: 2.0.77 (user setup)
VSCode Version: 1.99.3
Commit: ba90f2f88e4911312761abab9492c42442117cf0
Date: 2025-11-13T23:10:43.113Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Windows_NT x64 10.0.22631

Does this stop you from using Cursor

Yes - Cursor is unusable

3

Thanks for reporting this! To help troubleshoot:

  1. Which C# extension do you have installed? (You can check in the Extensions panel - is it “C# Dev Kit” or just “C#”?)
  2. Could you open the Output panel (Ctrl+Shift+U), select “C#” or “OmniSharp Log” from the dropdown, and share any errors you see there?
  3. Does the project build successfully from the command line (dotnet build)?

This will help us figure out what’s going wrong!