With RS4 I get on reboot or shutdown ( from time to time ) a application popup with this message:
explorer.exe - Application Error : The instruction at 0x00007FFD1C823442 referenced memory at 0x0000000000000000. The memory could not be read.
The adresses change from time to time. I used the same wccf as in RS3. Within RS3, no problem with explorer.exe mesage.