These linked branches may not be a full solution but:
1. they log the underlying problem (which is "eaten" by bad error handling at present); and,
2. they avoid crashing USC when the issue is encountered and allow a second attempt to turn the screen on.
Note:
lp:~alan-griffiths/mir/better-error-reporting-in-MultiThreadedCompositor-start
lp:~alan-griffiths/unity-system-compositor/report-warnings-instead-of-crashing
These linked branches may not be a full solution but:
1. they log the underlying problem (which is "eaten" by bad error handling at present); and,
2. they avoid crashing USC when the issue is encountered and allow a second attempt to turn the screen on.