Resolution: Cannot Reproduce
Appearing symptom is again related to masking exceptions in user32.
symtom in r73077 & r73036:
you click file and the application crashes due to unhandled exception.
symtom when reverting either r72495 or applying message_p.patch from
appeased, no crash but an error-box instead: r73077-internalApplicationError.png
(this is how 0.4.3rls will behave like due to reverting r72495)
Still not, what a user would want to see, we have to prevent that exception from being thrown at all here, I guess.
We want to see neither a crash, nor a message-box here.