Even Google didn't come up with a usable result for this error message. It was an internal verification error according to the dialogue box, along with the cryptic "could not find itemframe we just now checked in" (itemframe is all one word).
Do any of you have insight? CS6 on a system newly upgraded from Win7 to Win10. Yeah, I know...I'm one of those who can't resist sticking his tongue in the fan.