Visual Studio 2019 with C#: Deactivation of "Optimize code" crashes my project

Question

I Visual Studio 2019 with C#.

I try to deactivate "Optimize Code" for a Release build in the project settings.

But if I deactivate this feature I can not reopen my solution anymore, when I start Visual Studio I get this error:

An error occurred in 'Solution 'Test' (14 of 14 projects)' while attempting to open 'Test'

The document 'D:\Data\Source\tests\test\test.csproj' is already open as a project or a solution and cannot be opened in an editor at this time.

How can I deactivate "Optimze code" without this error?

I have tried most of the suggested solutions the Ihave found for this error message, like deleting.suo file or remove and add the project... but none worked.

Answer 1

You can edit the csproj directly - it is just xml. If this is a new-style SDK csproj, then you're looking for:

<Optimize>false</Optimize>

or

<Optimize>true</Optimize>

However, it sounds more like a hung background process somewhere causing problems. I hate to say it but: have you tried turning it off and on again?