The ZIP archive is missing critical files, or the files inside have the wrong names or incorrect data signatures, making them unrecognizable to the emulator's current database. Step-by-Step Solutions to Fix the Error for Free
If you are using RetroArch, ensure your FBNeo core is updated via the Online Updater before troubleshooting your ROMs.
That said, the emulation community thrives on preservation. Many "abandonware" sites offer ROMsets for games over 20 years old. Because arcade hardware degrades, digital preservation via FBNeo is the only way to play these games forever.