SIMCTL error

Today, debug runs of an iOS app have started failing sporadically with a message to say compilation failed and I may want to delete the file and start again
unexpected data returned from simctl

The system debug log contains this:

Mar 15 15:53:32 JeffTuls13inMBP[33721] ( Failed to bootstrap path: path = /Applications/, error = 2: No such file or directory
Mar 15 15:53:33 JeffTuls13inMBP[33721] (UIKitApplication:com.ursasoftware.myapp[3f4b][rb-legacy][33856]): Service exited with abnormal code: 1

Any clues there?

First thing I would do is Simulator menu > Hardware > Erase all content and settings.

Did you try with another simulator device?

That works
Shutting it all down and starting up again seems to help too.
I just cant work out what the problem is.