Sounds like a botched installation... Please go straight to posting that URL. <img src="https://www.ubbcentral.com/boards/images/graemlins/smile.gif" alt="" />
I had this same problem after installing the freeware version of the product which I downloaded a couple of days ago. I was able to get past it by manually creating forum directories under the ubb directory and using chmod to make them 777. You will probably see the first forum under ubb as Forum1. Create Forum2, Forum3, etc and make the permissions 777. Possible cause: I hit update threads in the control panel before any posts had been made to any forum besides the first one. That is about the only thing I did which was not strictly following install directions. Jerry Karin