It possibly may need updated if you haven't ran one in a while, or the cache may need cleaned. It could also be an app you just recently downloaded. If none of that is the problem, Do a hard reset and reboot in safe mode, then do a cache cleaning again. You'll just have to sign back into a few apps once it's finnished but it should fix the problem. If you don't know how to get into the boot loaders or reset modes.. look up your device on Google and type it in..there should be directions someone wrote somewhere. Them modes also have clean and formatting options as well as factory resets. Good luck and I hope I helped in some way