METHODS :
Clearing the Cache memory :
- Go to settings.
- Head over to applications.
- Open all applications/manage applications.
- Move onto Google Play Store.
- Simply clear data and clear cache.
- Reboot your device.
- Cheers! You probably fixed out Error 921.
Adding another Google account:
- Head over to Google Play Store app.
- Move onto Accounts.
- Press Add Account.
- Add your new Google account to the Play Store.
- You are all set to REMOVE error 921.
