A. 1. Free up device storage: Go to Settings > Storage and check if you have enough free space. If not, delete unnecessary files or apps to create space. 2. Disable battery optimization: Go to Settings > Battery > Battery Optimization, find Nicegram, and select 'Don't optimize'. This can prevent the app from being closed by the system to save battery.

B. 3. Restart your device: Sometimes, a simple restart can resolve issues with apps closing unexpectedly.