can make a diffuculties whis update / install apps, this eror: retrieving information from server RPC:S-5:AEC-0 one day just appeared on my phone. However this is a way how I found a solution to fix the RPC:S-5:AEC-0 error:
I tried these steps what helped other people:
Go the Settings app, click apps, then select “All”
Now your Google Play should work properly.
For those who don’t find this working, try this solution – worked for me and many others:
THEN Play store will behave again. You may need to restore sync etc. settings due to the account removal and reinstatement, but not a big issue – you’ll be prompted if and when that’s needed.