One user of mb sdc4 tried to activate Xentry and need to open "configAssist", got problem with it " unable to access service..." So he was unable to go through as the PDF guide on desk, to activate.
obd2shop.co.uk chief engineer solution:
Enter into "Device Manager" to find "Service" then "configAssist ", then click on "Start" and "Ok". The problem will be solved.
Good luck!
mb sdc4 tech support: www.obd2shop.co.uk