Safe Mode puts your phone in a diagnostic state (returned to default settings) so you can determine if a third-party app is causing your device to freeze, reset or run slow.
With the device powered off, press and hold the Power button (located on the top edge) until the Samsung Galaxy Note Pro logo appears then release.
With the Samsung logo onscreen, press and hold the Volume Down button (located next to the Power button) until Safe mode appears in the lower left of the screen then release.
Device goes through the entire boot up process before showing Safe mode. This may take up to 45 seconds.
With Safe Mode enabled, test device and app functionality. If the previous issue fails to occur, the cause has been isolated to a third-party app and all recently installed or updated apps should be uninstalled.
Power cycle device to disable Safe Mode then reinstall and test each app one at a time to identify which app is causing the problem.