Clicking apply exits the game, it's normal for it to exit when you apply a mod. It didn't "crash". I do believe it'd be nicer if the game gave a message box at the end like "Mods applied successfully, please restart the game, exiting..." and an ok button.
The yellow bits in your screenshot happen every time you exit the game, applying a mod or not. The other errors are it looking for a info.txt file, add that to your mod folder and they go away.
You appear to be trying to wholesale replace the files, are you using version 0.5.19b? Older versions wouldn't handle correctly replacing a multi-line variable. However, honestly, I don't like this approach. Doesn't work well if say you wanted your mod to play nice with someone else's mod. Instead I'd do it like this:
This works, at least with 0.5.19b, but probably with most older versions too since it only adds a simple var and modifies a function. It works in a manner that would play nice with other mods. You could have 20 mods like this, each adding their own regions, and as long as they named them something different, they'd all work.