You may get this error RPC:S-7:AEC-7 and RPC: S-7: AEC-0 on Play Store or Blue Stacks. Basically, the error says that there is an error retrieving information from the server, it may also be because of synchronization where the device / app cannot synchronize.
Bluestacks is an emulator so the steps below will work both on your phone and bluestacks. This is a technical glitch, which can be resolved with the following steps.
If after following the steps below; you’re still unable to fix this issue let me know in the comments and i’ll assist further.
Follow these steps to fix the issue
Open Bluestacks and click the top bar on the right or click the time area and slide it down.
1. Click Parameter. if on Bluestacks and if on Android Phone, go to Settings -> Apps
2. Swipe to right and choose “All”
3. Locate Google Play Store and click on it/tap it to open.
4. Tap or Click Menu
5. Click Force Stop
6. Click Clear Data
7. Then, click the arrow on the top left and return to applications.
8. Choose Google Service Framework from Apps
10. Click Force Stop
11. Then click Clear Data.
12. Reboot the phone, or if it is emulator then restart it.
One of these methods above should fix this for you. If none of them works, then a reset to factory defaults is needed. Make sure you back up your data to Google by syncing.