The Eye of Judgment: Legends

[kikix12]

The game loses track of its save data. At some point in the story (after sixth or seventh mission or something like that) it just shows that there is no startup save data found and that it needs to be present on the memory stick to play the game.
I've no idea how to bypass that since I've no idea what even causes this error. The game saves fine, there was no problem before that stage either.

It's the same on PPSSPP 9.9.1 and 1.0.1.