Help System UI has stopped

[Karlwebdesigner]

Im using a Samsung mega, I try to shut down phone and do a "Power on and volume down" step, but a warning appear before I can go into recovery menu, the warning says if I press volume up, it might cause critical errors to installed apps, the volume down key says reboot, please help me...

 

[dontpanicbobby]

Sounds like one of those options leads to a Factory reset. A Factory reset restores your device to like when you bought it. No contacts or user installed apps will be left after a factory reset. Android assumes you use Gmail so any contacts you have there can be easily restored damn near automatically afterwards. User installed apps are just gone.