title: vs solution not finding [Fact] unit tests
body: <p>I have a VS2017 Pro solution with a Tests class containing all unit tests (decorated with [Fact]). For some reason, VS isn't discovering these tests. Several tests were added by a previous developer and I just added a new test. I asked the previous developer and he said that there might be a mismatch in test runners in my local solution. What steps can I take to try to fix this?
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