Have you tried the official fixes above? If the Play Store still won’t work on Android 5.1.1, consider switching to a custom ROM like LineageOS (if available for your device) to get a more modern, secure Android experience – without a single "crack."
If your Android 5.1.1 device is malfunctioning, wipe the Play Store data, install the official APK from a trusted mirror, and accept that modern apps may not support your legacy OS. For the health of your data and your Google account, – it’s almost certainly a scam. google play store apk cracked download for android 51 1