Whenever I tried to hold down the home button to clear the background apps, it would say the System UI has stopped. Whenever I hit okay, it would return me to the home screen with a default background. I looked around on the internet and saw something about shutting down the device, holding the power + Down volume to do a reboot. However, it came up with a warning saying downloading a custom OS could damage apps, etc. I canceled it and then tried the combination again, but the same screen appeared. I then moved on to downloading a custom OS. Was this the right thing to do? Will it fix the issue or cause more? How long might this take and what exactly is being done?