I would first check and see if you are using latest version of Google Play. If you aren't, then I suggest updating it.
RPC:AEC:0 error is known as CPU/RAM/Device/Identity failure.
Try this to see if it will get rid of the error...
Go into "Settings", then into "Application". Now choose "Play Store" and then "Disable".
Now restart the device.
When it has finished restarting, go back to "Settings", then into "Application". Now choose "Disabled" and then "Play Store" and finally "Enable".
Another possible fix would be to...
First go into "Settings", then into "Application". Now choose "Play Store" and then "Clear Data & Clear Cache".
Next go to "Accounts", and select "Google", then "Remove Account".
Now reboot your device...