Try setting ShowUIWorld="false" in the game.xml. Then check the menu selection entries in the QC selector. You're looking for something like the location or the aircraft saying [-] to indicate that the program can't find the requested file. Usually setting it to something that has a real entry lets you reset ShowUIWorld="true" and start without the error next time.
I would also double check my pylons, weapons, and sound files again just to be sure.