Do you have the modesetting module for X installed? Doesn't appear so.

Cheers,
Michal

That does appear to be missing from that system image.

Did we miss that in the requirements documentation somewhere? :o

/edit
That fixed it, and it is functional now.

Should /usr/lib/displaylink/DisplayLinkManager be eating a large amount of CPU (most of or more than 1 core) ?

Glad it's fixed. The CPU usage - it depends. It is discussed in more detail here.

Cheers,
Michal