Unit tests fail for mixed .Net Core/csproj projects since 2016.3

 Hi,

We are running VS2015 Update 3 and we have several projects which use both project.json and the classic buidl with csproj.

We cannot run the Nunit unit tests from the IDE anymore. It was working fine with 2016.2.

Here is the error:

2016.12.20 11:29:03.637 ERROR Run: e386d0e1-7eb4-49c8-83e3-79359bab82b4 - Faulted
2016.12.20 11:29:03.637 ERROR System.InvalidOperationException: Failed to get child process StartInfo for dotnet test
at JetBrains.ReSharper.UnitTestFramework.Launch.Stages.RunTestsStage.<>c__DisplayClassc.<StartSingleRun>b__8()

It is trying to run "dotnet test" even though the project is opened with the regular csproj.

It is quite cumbersome since we have at least 30 of those mixed projects. There is no option to disable .net Core integration.

Thank you!