It can be difficult to lock these errors down, but there are a few steps you can take.
Have you tried pulling out your battery while the device is turned on. Then wait about 1 minute and place the battery back in.
You can try booting your device in safe mode KB17877
You can also check your device logs to see if it is an app that is acting up. KB05349
There should be an exception with the cause beside the entry.