VS 2015 diagnostic tools failed unexpectedly when running multiple instances of visual studio

I ran into this same issue today, and restarting VS didn't help either. I followed the logging from this question: Visual Studio 2015 diagnostic tools no longer working and didn't get anything helpful from there either.

What ultimately fixed it for me was ending the process named "StandardCollector.Service.exe." From the logs, I believe this is the process actually having the problem, and it doesn't close on its own when closing VS.

It only starts up when debugging, so perhaps it is easily orphaned somehow and then subsequent VS instances can't use it? Just closing and reopening VS while the same Collector process was running (after fixing the issue) seems to work fine though.

After trying to kill various processes, restarting Visual Studio, and various things like that, I couldn't get diagnostics to work. Restarting the computer fixed the issue