Broken Google Play on cm 10.1.2 I've updated cm from 10.0.0 to 10.1.2, and after updating the gapps too, several things are broken, including Gmail and Drive.

Now, Google Play lists them at "updatable", but it is broken and refuses to update any app, reporting Error retrieving information from server. [RPC:S-5:AEC-0].

Some google services apparently work (Contacts, Calendar), so I guess it's no login problem.

I've tried wiping data of a few related apps, but it didn't help.
The error [RPC:S-5:AEC-0] is down to having to remove your google account and re-add it again. 

If your account is primary google account, the only way you can remove it is to factory reset and re-install everything! That is the only known cure and quoted by Google themselves! Do not think they are taking it seriously enough. It broke on a previous update to Google Play Store about two months ago.

I get that too, if keep trying over a few minutes, it will eventually update, not successfully though. 

I do think its more of an issue on the Google system itself in conjunction with Play store app. 

It's not just confined to AOSP JB/ICS or CyanogenMod, I get in on Gingerbread too.

PS: As matter of curiousity - do you have Google 2-step account verification active on your account?