I had just opened up my ftp program to upload a modified theme, clicked on the theme folder to place it in it, and my husband came in the room to ask me a question. I turned to him, and then turned back to my computer, and found the whole theme folder gone! I must have had my mouse over the delete button and accidentally deleted it in the moment I was turned away.
So now what do I do? Should I just download the whole Moodle and reupload the theme folder?
Did you check Trash/Recycle to see if it ended up there?