For anyone who may have been following this thread I'm pleased to say we now have Mike back up and running. The problem was due to (for some unknown reason) our random number generator (used for creating unique squawk codes) became stuck in a loop whereby it was constantly creating a squawk code of 1111. Mmmmmh, not very 'random'
Anyway, Mike is running with an interim fix until we release our next planned maintenance release next month.
Needless to say, if anyone else should experience this bizarre behaviour of PF3 becoming unresponsive after selecting a flight plan please let us know here on the forum.