@lumpy I can't identify any problem in your gamelist, in your screenshot the error that appears is what has already been said "Having lines longer than 4096 chars is pretty usual, the game synopsis in metadata may be longer.", Just that.
In Windows, opening your file with "notepad ++", I don't get this error, and it is the program that I use when I want to edit something manually in the gamelist.
Are you doing all the scrappe manually? I recommend using an external Scrapper, it is much more practical: