The CE-34878-0 error in Diablo 4 on PS4 can occur due to various factors, including software bugs, corrupted game data, insufficient system resources, or conflicts with system software.

After the system has finished installing, make sure to restart the console before launching the Call Of Duty Modern Warfare II again. Fix #3: Install system software updates.

Is PS4 error NP-34954-5 causing you problems? Read our guide on possible fixes for PS4 NP-34954-5 here!