MB SD C4 Connect Error OBD365 Technical support

Getting an error message when I try to connect to the vehicle. It says "Initialization of diagnosis multiplexer failed...." [fault (1.1)-1.501.9551]. I have only used the machine once and now this is happening. Can you help me with this please?

Solution:
1) SETUP problem.
If you bought SD connect compact 4, please check the setup information. If IP address, WIFI setup all is ok. Please see the video: https://www.youtube.com/watch?v=Ql3vKstL_4k
2) Software problem.
If you bought SD Connect compact 4, you cannot use ordinary star software for c3/c4. SD C4 software only can be used on SD C4, cannot be used on other star, like c3, c4, super star c3. Other C3, C4, SUPER C3 software cannot be used on SD C4 too. Check if you bought the wrong software.
Do you install other software on the PC or HDD? Do you use anti-virus software on your PC? Another reason is your software is destroyed.
3) Firmware problem or connection problem.
Check your connection, if cable is connected rightly and tightly. Cable has problem? Cable is the right one?
If cable do not have problem. Check your firmware. If your software HDD is internal, then do the self test. star diagnosis

http://www.mbstartool.com