VS 2017 RC generating an 0x8000ffff error when trying to debug xUnit tests


I'm trying to debug my .NET Core xUnit tests in VS 2017 RC. I run my tests via the Test Explorer window. While right-clicking a test and selecting Run Selected Tests works fine, selecting Debug Selected Tests does not:

I'm at a loss at how to get past this. I have tried restarting VS, doing a clean build, removing the .vs/ folder, and even updating to a newer build of VS 2017. However, nothing so far has worked. Does anyone have suggestions for how I can work around this? Thanks!

edit: My project has a Git repo here, so if you want to you're free to clone it and see if you can repro for yourself. The test assembly is in src/BasicCompiler.Tests/.

asked on Stack Overflow Dec 25, 2016 by James Ko

5 Answers


In my case with Visual Studio 2017 release version the unit test project failed with this error because for some reason the unit test project had a launchsettings.json file under the project "properties" folder. Deleting it resolved the debugging issue.

answered on Stack Overflow Mar 20, 2017 by Joe G

Try running Visual Studio as an administrator, it might resolve the issue.

In case you don't know how: Right click on the application icon, right click on the applications name and select Run as Administrator.

answered on Stack Overflow Jun 6, 2017 by Alec Ruderman

If nothing helps try complete uninstall and reinstall of Visual Studio. Errors in upgrades cause issue sometimes. Ideally IDE should prompt errors and ask you to fix them but I have noticed Visual Studio does not do that; even when you go to updater and reinstall them.

answered on Stack Overflow Oct 19, 2017 by Morse

I fixed this by updating Visual Studio 2017 to 15.9.6

Tools -> Extensions and Updates -> Updates.

answered on Stack Overflow Feb 3, 2019 by MDave

Restarting vs worked for me...

answered on Stack Overflow Jun 20, 2019 by Qwerty

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