I gotta admit that I experienced this problem a few days ago before making this mod and every-time I tried to modify an xtbl file the game was simply crashing even from the most insignifiant change of value from one of the tables.After I started to download some of the others people's mods from this website the game stopped crashing but if I made the slightest adjustment then it would crash.I decided to download and install Notepad++ and then get some XML tools for Notepad++ and then it all stopped.So your best bet is to get a decent text editor for editing those files.