All of a sudden 5 days ago my Nexus 7 would fail to update any application, with the error "Update for "Evernote" could not be downloaded due to an error. (Error retrieving information from server. [RPC:S-5:AEC-0])". I looked around on the internet for solutions. A lot of people recommended clearing data, enabling/disabling/clearing play services. None of these things worked for me.
In the end, I had to remove my main Google profile from the device, and add it back. Then all of a sudden the applications on my Nexus 7 updated perfectly. Hope this helps someone else.