I deleted the addons and I still have the same problem. It goes to the repair vendor, opens the repair window and does not click on repair, then flies off and the window closes. I have gold in my bag to repair. I noticed the vendor in Vengeance Landing would sometimes repair and sometimes it does not and just flies off. But the vendor in Uldum doesn't repair at all.
Just download AutoRepair from curse it will automatically repair once you interact with the repair guy link is here AutoRepair - Addons - Curse