My Mercedes W204 C250 sometimes cuts off when driving. At times, it cuts out and starts back up almost immediately as can be seen in the first half of the video in the link attached. However, sometimes it can come to a complete stop and thereafter refuse to start again as shown in the second part of this video. In this case, I often just have to wait a few hours or sometimes minutes, and it will eventually just start right up.

Video of issue:

 

If you have a scanner try to scan and see which modules are not responding, then check the wiring, it appears that it could be a CAN issue either from a bad wiring or bad module, there are videos on YouTube that go in depth on how to test the CAN network with a multimeter.

Let us know what you find!