Hi,
I have exactly the same problem It all started on a fine afternoon when my samsung galaxy tablet started slowing down, then froze. I closed all apps, restarted it but nothing. So, I ignored the situation only to realize later that for mysterious reasons I could no longer download anything from Google Play. I can dowload some stuff on Galxy apps but my samsung galaxy S4 phone has access to way more app choices on Google store and Galaxy apps and so did my Samsung Galaxy Tablet before November 6th, 2015. So after research on the issue, known error code RPC:S-7:AEC-0QDKT-H6BZ-LICBK the solutions proposed were as below:
1) Go to goole store and all likewise apps under settings»applications»manage applications and eraze cache and data for all of those google related apps. I did this and it did not help.
2) I was then to unlink my google accounts from google play store and relink them and try to to download something, an app, game whatever. This didn't work either.
It turned out that Samsung Galaxy tab 7.0 plus running on honey comb (3.2 version) has an outdated version of samsung android OS and Samsung has no solution in place to upgrade to a higher version apart from in a handful of countries in asia and middle east. So someone has upgrade your tablet backstreet. Alternatively confront Samsung about this situation. It looks like you, I and many others are being forced into replacing their tablets against their will. Meanwhile mine though bought in May 2012, it looks a week old, no scratches, never mishandled but dysfunctional. This is a rip off. Good luck with your situation from Canada. Don't even bother sending it out to an authorised repair place for Samsung. I did but they sent back my tablet stating it required no repair. I am lucky to be in a city where that kind of authorised organisation is and my answer from them was very quick. The famous'we cannot not help you, call Samsung'. Then I call Samsung and they tell me to call Google playstore and google play store refers me back to Samsung. That is the run around I got. Thanks God I had the time to go through all those unsuccessful procedures.
Best regards Elijah.