What follows is a possible solution for an access violation in FSUIPC that can suddenly appear.
Note: the symptoms look very similar to what is described in the “FSX fails to run after FSUIPC4 first installed” FAQ post. The problem is different in the sense that in that case it will happen before FSUIPC ran successfully for the very first while in the problem solved in this post it occurs after FSUIPC has been running successfully for some time already.
So the symptoms are:
FSX reports “Flig