Standard ISO dumps often lack the necessary patches to unlock the "free" DLC characters (such as Unknown or Dr. Bosconovitch), which originally required an active PSN connection to activate.
If playing on the RPCS3 emulator, enabling "Write Color Buffers" is a critical fix to prevent broken character outfits and textures. ps3 iso tekken tag tournament 2 fixed
To ensure your ISO version has all 50+ characters unlocked without a PSN account, follow this community-standard procedure: Standard ISO dumps often lack the necessary patches