I had this problem on beta and I don't know if you're in the same boat, but: 1) Delete your wtf and cache folders. 2) Copy your beta folder to the desktop, delete your C://Programfiles/world of warcraft public test folder, run launcher, let it "initiate" the PTR download, then let it run for a minute or two. Then, once it's started, pause it, then copy the folder from your desktop back into the newly created Program Files folder. Click "Copy and replace all." Hopefully one of these 2 works.