Hmm, I haven't encountered this problem in windows. The only way it could happen is if someone tries to use the global players folder instead of the players folder under application data. Installing over older versions may also cause trouble like this.
Thing is, you would have to have a backup of all the files, and make sure to change anything like if you leveled up. And copy those into the player file every single time you open a module. And then it still might not work.
I think the problem is in notepad date, why the error disappears when I edit the notepad correctly but whenever I went out and back, the same error happens.
Perhaps the game is not saving the characters properly, I could play when I got a whole other character personality and good to play! And it worked,
The problem is that the game're not saving the characters correctly.
I have same problem in XP. I was first time finish a game(elf start) and when I try load the character file it happens. And ALL data.txts in char_id.obj are empty. Anyway it's nice to see new versions since 2.2.0 and even with a start screen.