I had the same problem (or so I thought) in 7, but it ended
up that I can't delete folders that have anything in them. I first
had to delete the contents (in the Project Manager Pod), then I
could delete the folder.
Thanks for your help. In another thread, Peter G. also
suggested checking your local directory (outside of RH) to make
sure there are no files in the folder you are trying to delete. To
add, I found images that were still in the folder. I forgot to move
them. Finally, Peter G. suggested to use the Unused Files report. I
still have to try that.