I'm running all test cases of project (cmd + U) then all of sudden this error message pops-up with no reason. I'm using Xcode 9.4.
Any fix?
Is is possible you are running on device and it is locked?
The same thing just happened for me ("Error Generating Code Coverage" when trying to run all tests) and then I realized that Xcode was trying to build to my phone, which was locked. It ran ok on my phone after I unlocked it (and fine on the simulator as well).