Instruments: Target failed to run: already running on exited process

Question

I quit out of Instruments, the iPhone simulator, Xcode, and unplugged and reconnected my iPhone. I still get the following error.

This first answer below didn't help.

Answer 1

Try to switch off your iPhone and restart it. Sometimes this is the only way to fix a problem with some process being hanged in the debugger, maybe it also works for Instruments.