Open FBNeo and go to Help > About . Note the version number (e.g., v1.0.0.3).
Many users search for a "fixed free" download or a magic patch, but the reality is that this error is usually a mismatch between your file and the emulator's strict requirements. romset+is+unknown+fbneo+fixed+free
In this article, we will explain why this error happens, how to fix it permanently, and where to find ROMs that work flawlessly with FBNeo. Open FBNeo and go to Help > About