Ahh – its 3am and that pList config file you have been pouring over suddenly won’t compile anymore in xCode ;(
Looking through lines of xml markup at these hours isn’t fun (or easy).

Solution: Terminal + plutil!
Thank you for whoever wrote this genius little utility at Apple.
Just type plutil [path to your plist] and hit return. It will list any formatting errors and even give you a line number.
Genius.