Do not keep your BIOS files in restricted system folders like /Android/data/ . Instead, create a new folder directly in your Internal Storage (e.g., /Internal Storage/PS2/BIOS/ ) and move your .bin files there.
If you are using a Xiaomi, POCO, or Redmi device, users have reported that toggling MIUI Optimizations in Developer Options can resolve permission blocks. Common Causes of BIOS Failures aethersx2 failed to write bios image
Android 11 and newer often require explicit "All Files Access" for emulators. Do not keep your BIOS files in restricted
Sometimes the BIOS file is the wrong size or is a raw dump your emulator dislikes. You can attempt to convert it or verify its integrity. or Redmi device