Can't start PSX game on PSP

I'm using firmware 3.40 OE-A.

I've looked around everywhere but haven't been able to find an answer.

So far I have all the prx files in the correct locations, all the correct options enabled and disabled in recovery mode, a UMD in the PSP, etc.

Even so, I cannot boot this game (DBZ Legends).

I just get an error. I can hold R when loading it to select the Pops version, but nothing changes afterwards. (Error 80020148)

Can anyone explain why? Is there some massive guide I could take step by step to ensure that this game will work?

I'll try remaking the EBOOT at some point but only if that's my only option.

Noone knows anything?

Surely that's not the case.

try and remake the eboot cus sumtimes you can get a faulty eboot

Did you put the game on
ms0:/PSP/GAME/DBZ Legends/Eboot.pbp

maybe it's this, cause sometime i put my psx game on GAME150, and it didn't work

my guess, cause i think you're trying to run it like an ISO, there is no config on recovery for PS1 games, also you don't need a UMD inserted to play them