It sounds like maybe it's an issue with getting information about a non-text clip..
Let's not worry about subsequent behavior after that error, since that is probably enough to stop the program from working.
If you exit the program and restart it, do you still get that error on startup?
If so i will send you a new version to test -- email me (firstname.lastname@example.org).
You might also try unchecking the "Capture Images from Clipboard" in the Image Capture tab, and restart -- and see if that solves the error; if so at least we will have a clue about the problem.