[NEEDS INPUT] [CD] Can't sell gold poop from inventory

I have this issue with *all* manure, and it started about a day ago in the middle of a save. I could drag and drop manure to the part of the inventory that says "drag here to sell". Now when I try, it says "this item cannot be sold or deleted".

Workaround: If I delete from build mode, I still get the money. 

I tried repairing my game. I tried a clear save with a new household and this glitch affected it, as well.