Your CFW/HFW version is lower than required by the multiMAN build. Fix: Update your PS3 firmware to at least 4.85 (or spoof your version if your CFW supports it).
: Plug the USB into the rightmost port of your PS3. Navigate to the Game column on your XMB, select Package Manager > Install Package Files > Standard , and select the MultiMAN file. multiman pkg
Disclaimer: Jailbreaking your PS3 and using backup managers like multiMAN exists in a legal gray area. Always own original copies of games you back up. This article is for educational purposes regarding system file management and homebrew software. Your CFW/HFW version is lower than required by