On very rare occasions you may run into an error that says "There was an error saving your question" on the Build tab (so rare that we couldn't get a screen shot). What this typically means is that the element or question was created without an ID being assigned. This makes deleting, moving and copying the question/element throw an error as well.
If you run into this the fix is pretty easy. Simply move all the elements on the same page as the corrupted question to a new page, leaving just the corrupted question/element on its own. Then simply delete that page and recreate your question/element.
