If you are seeing errors after downloading the app, please check this list :
1. Please consider this link : https://support.google.com/googleplay/troubleshooter/4592924 for troubleshooting steps.
2. 919 error occurs when your network is unstable. Especially on wifi. So, we recommend using data when you download Azar.
3. Please clear your Google Play Store app cache and data. Settings → Application manager → selecting 'Google play store' app. → Clear data and clear cache. After doing this, try downloading again.