DON'T UPDATE TO macOS 10.13.4
DON'T UPDATE TO macOS 10.13.4 and DON'T use the DisplayLink Instaler 4.1.11 ... until they will have something which will work.
I cannot get now even a single video at all ! Just a blank black screen!
So how can I go back to 10.13.3 and uninstal the DisplayLink if I don't see anything on a screen? Any suggestions? Anyone?