I am using Visual Studio 2017 and am trying to create a .Net Standard 1.5 library and use it in a .Net 4.6.2 nUnit test project.
I am getting the following error...
Ran into this just now in a Unit Test project after adding MsTest V2 through Nuget. Renaming app.config (so effectively removing it) did the trick for me.
Having read through all the above posts, I'm still not sure why, sorry!