Can you give us a bit more information, and the actual build on the about page on the opl start menu/settings page?
What console you're using?
What format your USB is (fat32, exfat, cluster size?)
What controller setup are you using? a regular controller or ?
We need a clear description of what you're working with.
It may be something as simple as a bad dump, or turning on a game settings mode like 1, 2, and/or 6. It can vary.