Ive seen other people mention this issue, not sure Ive ever seen a "fix" though. 

Have you ran the Refresh Updates option from the Updates drop down menu?  Maybe an update didnt install properly, this could correct that issue.

I did all of the steps that you mentioned. I ended up backing up that particular client from a 2nd computer, and replacing the file. Basically, started return over. Thankfully, I wasn't too far in. Thanks