the error drives me crazy

[[Unknown]]

It's hard to tell if that's actually related. This error can mean several things:

1. Some games are written by the developers to access files that don't exist. Commonly, they will try "somefile.dat" and then maybe "somefile.dat.gz". The first one only existed on their development machines, but they didn't bother to delete the debugging code.

2. You may have a corrupt ISO. Make sure you're not using some ISO from the internet; those are often hacked, edited, underdumped, or otherwise corrupted. It is better to pull from your actual disc / etc. to make sure you have a clean copy.

3. There could be a bug emulating the game making it attempt to access this file when it shouldn't.

4. Maybe you're using some translation patch that has a bug (not sure if you're playing the original or not)?

There's a mixed bag of reports on this game:
http://report.ppsspp.org/game/NPJH50486_1.01

It's been reported as Perfect and Playable by many users, but also as completely broken by others on the same PPSSPP versions. This makes me think it's related to the disc.

From Google, the crc should be 38888433.

-[Unknown]