Hi @ooo ,
Thank you for reporting it in Microsoft Q&A.
Could you tell me your project type and the C# components you have installed?
Before installing the workloads or components, please first close all instances of Visual Studio and update your Visual Studio 2019 to the latest version. Then, check if you installed the correct components for your project.
If it doesn’t work, please try to uninstall the current C# components and install it again.
By the way, in order for us to reproduce your issue, please share us more details to investigate further.
- If the answer is helpful, please click "Accept Answer" and upvote it.
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