Hey! i'm new to codinghs and in need of help

[CaNANDian]

You can either stick in a UMD to make it work or do as Tact said and change the ISO mode to the sony one or No UMD mode.

[Pain_ELementaL]

Flashing your PSP to custom firmware may have corrupted the security file in the flash memory that tries to keep PSN games from being pirated. If worse comes to worse, I recommend deactivating your PSP from your PSN account, and re-downloading the game.

[Scruffy120]

Flashing your PSP to custom firmware may have corrupted the security file in the flash memory that tries to keep PSN games from being pirated. If worse comes to worse, I recommend deactivating your PSP from your PSN account, and re-downloading the game.

correct but not so 'correct' easier way out
go into the psn store, like sign in, then select management from the settings in there, and find the activate button, what you did is when you update your PSP, it formats the flash's (it only backs up a few things, security not being one of them), so next time to save a little time enter the recovery menu and enable flash 2, copy the file 'act.dat' i belive its called, and just store that on your computer, when time comes to update throw it in the flash2 and its all good =] or download the SFCO iso lol