What version is currently installed, and what operating system are you using? A lot of people are experiencing the same error message as yourself. I was able to get to 13.0.1 on a Win 7 64 bit system, by using the direct download page as opposed to the Application manager.
The Application manager is telling me there are updates available, but I think it is wrong, and that 13.1.# is for Mac systems regards CS6. It's only a few hours till the CC versions go live, and that should sort out any problems.
All is good now, I followed the instruction in this link, http://forums.adobe.com/message/5396792#5396792%235396792 and uninstalled and reinstalled my Creative Cloud version of Photoshop CS6 then reinstalled it and went into Help>Update and expanded all the updates, the update they mentioned, 220.127.116.11 update was not there so I just clicked on continue and everything successfully updated, pass it on, thanks for getting back to me.