Black screen or pointer only

[Kbyte]

Hi!

I've connected my Dell 3100 docking station with Debian (unstable/exp), lastest Kernel (4.8) and lastest displaylink drivers.

Now the monitor attached to the docking station is black or shows only the pointer. I made a screenshot, but it shows the whole desktop.

Kde isn't the cause, because I made also a test with fvwm.