Deck Backing Image Not Working

Where are you two dragging graphics one? Dragging from your computer file folder? From the Art Library folder view? A graphic listed in the Art Library on the Sidebar? There's a known issue that you can't drag from Art Library folder view to the card decks, but you can drag and drop items from the Sidebar.

My apologies for the delay on my response to this. This past week I was in the process of completely restructuring our bug ticket system to be, hopefully, more orderly. I was able to drag an image from my desktop into the card back section of a card deck with no issue (I tested with a JPG and PNG file), so it may be a graphic issue you're dealing with. Can you tell me what sort of file you were trying to upload as the card back? Also, did you check to see if you have any browser extensions/addons that could be causing issues with dragging and dropping graphics into the card back image window?