I’m having this same problem and have been doing searches this afternoon for a solution. In addition to the “already exists” message that sbernado is getting, if you look at my dashboard it says that I have “3” categories, but if you go over to the Categories page there is only “uncategorized” listed. (I’m just setting this blog up and only had one parent with a couple of children to start with that I deleted while doing some reconfiguring.) – Lori