Hmm, unusual for sure. I can see the cache file having a problem in building with the spaces in the ROM filter. The crazy part to me is that GameEx pulled an old cache file from thin air somehow. I had a similar issue many builds ago, but not sure when it was resolved. I was waffling between using GoodMerge SNES roms, and for some reason when I switched to a folder that only had US roms in it the list was empty. When I switched back to the 7z files, the list came back up. To fix it I ended up deleting the emulator completely from GameEx and redoing it. Never had an issue again. *shrugs*