One of our customer had the device not connection problem when using Mercedes MB SD Connect C4 diagnostic system. Here is the working solution provided by mbstartool.com engineer.
You are required to update the MB SD C4 firmware follow the guide here:
Install SD Connect C4 battery
He did follow the solution but still had the file for software update error
The problem is that the names are wrong in file “SDconnect Toolkit “, you need to correct them as:
Update_automatic , Update_manual ; Update_Special
this was the right solution of the Problem.
The Names were wrong.
Thank you very much for your help.