The emulator core cannot read the file extension or the file is corrupted.
In 1994, Sega released Sonic & Knuckles featuring a unique "Lock-On Technology" cartridge. Players could insert Sonic the Hedgehog 3 into the top of the Sonic & Knuckles cartridge to combine both games into the definitive experience: Sonic 3 & Knuckles . sonic knuckles wsonic3bin file install
Open your Steam Library and ensure the SEGA Classics collection is installed. The emulator core cannot read the file extension