VS 2022 Not showing red squiggles and no intellisense anymore, at least, underUnity

Question

VS 2022 Not showing red squiggles and no intellisense anymore, at least, underUnity

vanderghast 1

Using Visual Studio 2022, I have lost the squiggles red wavy line when there is a typo error (faster to spot it than to move to the console to see error messages) and I have also lost intellisence allowing us to "discover" the methods and the signatures of a given type following the "dot" after writing the variable name. Sure, I "won" the various [tab] suggestion from AI, but those are less informative than intellisense ( AI targetting a, one, solution, intellisense targetting multiple, many, possibilities), not saying that AI is sometimes just doing too many things at too many places when I "tab" for a red or a green or a whatever-I-am-not-sure-what-tab-will-do, which I like when it is about a comment, but not when it is a piece of code.
Anyhow, the proposed solutions to the problem don't really apply since I am under Unity and the required options to display the wiggly-red-line is effectively checked.
Other suggestion to get back the wiggles AND intellisense? (intellisense, that word still exists? I got the wiggly red line right now, here ! ? </ironic> )

Surya Amrutha Vaishnavi Lanka (INFOSYS LIMITED) 2,285 Reputation points Microsoft External Staff

2026-06-01T07:32:59.4833333+00:00
Thanks for reaching out!
This issue is very common with Unity and Visual Studio integration and is typically caused by a broken connection between Unity and Visual Studio or editor settings overridden.

Please follow the steps below in order:

Verify IntelliSense & Error Highlighting Settings in Visual Studio Open Visual Studio and go to Tools next Options and select Text Editor, check the C# auto list members and parameter information

Disable AI or Extension Interference. Some AI or extension-based completion tools override IntelliSense, so go to extensions and select Manage Extensions and temporarily disable- Intellicode, AI completion tools, ReShapper. These can replace/disable the default IntelliSense list and squiggles.

Re-open Project Properly from Unity This is a critical Unity-specific fix. So close visual studio and open Unity and click Assets - Open C# Project This forces Unity to regenerate and reconnect the solution files correctly.

Go to Edit and select Preferences to External Tools.

Set External Script Editor to Visual Studio 2022.

Enable all .csproj generation checkboxes.

Clear Corrupted Visual Studio Cache Close Visual Studio, and Delete these folders from your project .vs,bin, obj and reopen solution from unity.
vanderghast 1 Reputation point

2026-06-03T19:38:57.8233333+00:00

The squiggle lines and the IntelliSense reappeared after I "reset" the External Scrip Editor (is was changed for selection from the file extension).

THANKS a lot. Much better now.

1 answer

Your answer

Surya Amrutha Vaishnavi Lanka (INFOSYS LIMITED) 2,285 Reputation points Microsoft External Staff

2026-06-01T07:32:59.4833333+00:00

Thanks for reaching out!
This issue is very common with Unity and Visual Studio integration and is typically caused by a broken connection between Unity and Visual Studio or editor settings overridden.

Please follow the steps below in order:

Verify IntelliSense & Error Highlighting Settings in Visual Studio Open Visual Studio and go to Tools next Options and select Text Editor, check the C# auto list members and parameter information

Disable AI or Extension Interference. Some AI or extension-based completion tools override IntelliSense, so go to extensions and select Manage Extensions and temporarily disable- Intellicode, AI completion tools, ReShapper. These can replace/disable the default IntelliSense list and squiggles.

Re-open Project Properly from Unity This is a critical Unity-specific fix. So close visual studio and open Unity and click Assets - Open C# Project This forces Unity to regenerate and reconnect the solution files correctly.

Go to Edit and select Preferences to External Tools.

Set External Script Editor to Visual Studio 2022.

Enable all .csproj generation checkboxes.

Clear Corrupted Visual Studio Cache Close Visual Studio, and Delete these folders from your project .vs,bin, obj and reopen solution from unity.
vanderghast 1 Reputation point

2026-06-03T19:38:57.8233333+00:00

The squiggle lines and the IntelliSense reappeared after I "reset" the External Scrip Editor (is was changed for selection from the file extension).

THANKS a lot. Much better now.

Answer 1

In Visual Studio, red squiggles and IntelliSense come from the code editor’s analyzer and IntelliSense engine. When they disappear, the issue is usually with editor features being disabled or overridden.

Try these steps in Visual Studio 2022 (even when working with Unity projects):

Verify squiggles and Quick Actions are enabled
- Squiggles (wavy underlines) show errors and warnings as you type, and a light bulb offers Quick Actions to fix them.
- In Visual Studio, open Tools > Options.
- Go to Text Editor > C# (and All Languages if needed) and ensure options related to:
  - Error reporting / “Underline errors in the editor”
  - “Show live semantic errors” are enabled.
- Squiggles should appear again for syntax and compiler errors, and the light bulb / screwdriver icons should show Quick Actions such as Add using or Generate method.
Use Quick Actions to confirm the analyzer is working
- Intentionally reference an unresolved type (for example, XmlReader in a C# file) so that a red squiggle appears.
- Place the caret on the type and press Ctrl+Period or click the light bulb.
- If the analyzer is working, options such as using System.Xml; or Generate class will appear and applying them should remove the red squiggle.
Check for extensions overriding IntelliSense
- IntelliCode and IntelliSense can be hidden or altered by extensions that replace the completion UI.
- Disable any completion/AI/autocomplete extensions temporarily:
  - Go to Extensions > Manage Extensions.
  - Disable extensions that provide their own completion lists or AI suggestions.
  - Restart Visual Studio and test IntelliSense again.
- If IntelliSense suggestions (member lists after .) and starred IntelliCode items reappear, re‑enable extensions one by one to find the culprit.
Confirm IntelliSense features are active
- IntelliSense should show member lists, parameter info, and automatic code generation options (like Generate method, Generate property, Generate class, Add using).
- In Tools > Options > Text Editor > C#, ensure IntelliSense features are turned on (completion lists, parameter info, etc.).
- In the editor, type variableName. and check that a member list appears; if it does, IntelliSense is functioning.
If IntelliCode is specifically missing
- If IntelliCode “starred” suggestions are not visible even when IntelliSense lists appear, an extension may be overriding the UI.
- After disabling such extensions, if IntelliCode still does not show, use Help > Send Feedback > Report a Problem and mention IntelliCode.

These steps restore the standard Visual Studio behavior: red/green squiggles for errors and warnings, Quick Actions via the light bulb, and IntelliSense/IntelliCode completion lists and automatic code generation, even when editing Unity projects.

References:

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VS 2022 Not showing red squiggles and no intellisense anymore, at least, underUnity

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