LPII to LPIII stream read error

Hi everyone. I'm new to this forum, I came here looking for informations about Laxius Power.
Playing the games I've got a problem when I tried to save my game in LPII to export it in LPIII. I copied the map723.lmu file in my LPII folder and loaded, but when I clicked on the last letter, before the corridor where I'm supposed to save, the game crashed with an error message of "stream read error". Should I try installing another version of the game?