> error message that simply says "Something went wrong."

Actually, are there HCI guidelines for communicating inexplicable internal errors to the user? I definitely write assertions that really should never ever fail - if they do, we are in a completely unanticipated state. Either there's been a truly massive logic bug, or maybe even a memory error flipped a bit, but in either case, I have no idea what state the program is in or what caused it to get there.

What would a good tech writer tell the user in this situation? I can't think of anything all that much more helpful than "something went wrong". Maybe "There is a serious bug in the program, totally our fault, please help us by reporting it"?

If the user is to report a bug, then any additional information would be better than "Something Went Wrong." "Something Went Wrong" is the equivalent of the guy who calls into the IT helpdesk and says "My computer isn't working."

Surely, somewhere in the code, there is an if() statement, and you're displaying the "Something Went Wrong" dialog in the else() clause. You could at least add some context that the user can copy down, so that the bug report that will come later helps you find the bug.