What are you trying to copy & how are you trying to copy it? Usb thru file manager or ftp like filezilla? If your trying to write to the flash such as a boot loader, then you have to enable the ability to write to the flash. but writing anything to the flash is very risky if you don't understand what your doing, you can turn your ps3 into a paper weight.
i try to copy mod menu to gta v with multiman and it fails on 1 %
and my ps3 crashes if i send message on psn, open invite anything that needs open ps3 keyboard
Did you make a backup of the original GTA files before you tried copying the modded files over? what kind of menu sprx or update.rpf? If you have the original files, try copying them back onto the machine. Your on rebug rex, but is your machine cex or dex? what region GTA are you using? I have original files for GTA5 BLES if that helps... Your firmware is not broken, you have something corupted & just need to fix it. Don't mean to bomb you with so many questions but the more info the easier to diagnose the issue..
i dont have backup , update rpf mod menu , i already have another mod menu rpf i removed it and i cannot copy new one , my machine is cex , i dont remember region