Exceptionally Unbalanced
I got a new error message today, that I couldn't help but take a screenshot of.
I was messing around with some code and wondered if it would work, so I hit F5 (as you do...hey, it's not as if I'm playing thermo-nuclear war or anything :) and it gave me this message:

My group delimiters are not balanced huh? What group delimiters? It sounds like I'm messing with a regex or something (which I wasn't). Now, it was easy to figure out what I'd done wrong (RTFM on the line that went FOOM) but this specific message turns up absolutely nothing in Google (which is strange). It also gives no indication of what I should do (normally on strange messages there's an inner exception which gives better info - but not in this case :)
But anyway, it made me laugh.