Interesting, because I catch all unhandled exceptions in the main program loop and print their stack-traces to ErrorLog.txt. It seems that you circumvented that in some way or that this message gets generated even before the exception bubbles up far enough for me to catch it.
I will add even more exception handling in the next editor version, in the hope that this elusive exception gets caught in some way.
Until then I cannot really do much. Sorry.