Go to Settings > Accounts > Google → Remove your account → Reboot → Add the account again.
If you are using a legacy device running Android 5.1.1 (Lollipop)
This is a backend Google Services error. Update Google Play Services separately. Download the latest APK for API 22 (Android 5.1.1) from APKMirror (variant: -47635831 for arm64 or -47635829 for arm).
By following these steps, you should be able to download and install the Google Play Store APK on your Android 5.1.1 device.
: Go to Settings > Security and toggle on Unknown Sources to allow installations from outside the Play Store.
This is the story of "The Relic"—an old but reliable tablet running Android 5.1.1 (Lollipop)