# Android - Frequent Questions and Problems
This page contains a list of the most frequent questions and technical issues that users run into.
# Cannot set live wallpaper on Android lock-screen
Depending on your device manufacturer and the Android launcher that you are using, it may not be possible for you to set a live wallpaper on your lock screen or to only set the same wallpaper as on your home screen.
When previewing a live wallpaper in Wallpaper Engine on your phone, long-press a few seconds on the check-mark symbol in the upper right corner. This brings up the live wallpaper screen of your phone. Depending on your manufacturer, you should now see the option to set the wallpaper on your lock-screen - if this option does not appear, your phone does not support live wallpapers on the lock-screen. The following phone manufacturers are known to not allow live wallpapers on the lock-screen on all or some of their devices:
# How to unset Wallpaper Engine wallpaper
If you wish to stop using a Wallpaper Engine wallpaper, you can simply assign a new wallpaper in your Android settings. Wallpaper Engine is just another wallpaper to Android and wallpapers cannot unset themselves.
Alternatively, you can uninstall Wallpaper Engine entirely which will cause your phone to revert to its default wallpaper.
# Android wallpaper regularly disappears or crashes silently
If you are using Wallpaper Engine as a wallpaper but the wallpaper disappears without any error messages after a few hours, days or weeks, it is likely being falsely terminated by your phone's power saving functionality. Under normal circumstances, Android should never terminate live wallpapers for power saving purposes but some users have reported this happening to them. This depends largely on your device manufacturer, if Wallpaper Engine disappears regularly, disable power optimization for Wallpaper Engine in your Android settings. This differs depending on your Android version and device, if you are unsure, search the web for ways to disable power optimization for apps on your exact mobile device name.