Error when running unit tests in visual studio: Test-case objects missing

Question

I'm getting the following error when running unit tests from visual studio using resharper:

Test-case objects missing for the following elements: ... Rebuild the project and try again

In the tooltip next to the unit test method it says: Inconclusive: Test not run and I think it said Unit test skipped at one point. Resharper shows a grey eye icon.

There's also a wierd issue with visual studio's Test Explorer. It won't show all my unit tests. In fact, it's missing over 200 of my unit tests. They just don't appear in the Test Explorer window. I do have a handful of tests that appear and will run just fine.

Things I've tried already: rebooting my machine, clean, rebuild, changing all dependent projects to use the same .net framework 4.7.

I'm using VS 2017 .net Framework 4.7, Resharper, and MSTest. All with the latest updates and versions.

Answer 1

I experienced this error after removing all nuget packages as I had changed my .net version and did not need any of them to compile.

After re-installing the MSTest.TestAdapter nuget package ReSharper started running my unit tests again as expected.

Install-Package MSTest.TestAdapter