I had this today and found a few things that if I switched to a different simulated device it was fine.
At the same time the canvas was not refreshing; after I quit both Xcode and the simulator and restarted the problem went away.
I suspect it's something to do with the simulator running the code for the canvas and trying to run the same code in a simulated device.
Stephen-NKS
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Last seen
User for