From this page you can download a driver for your DisplayLink® enabled USB graphics device that is incorporated in your dock, adapter or monitor. This software provides support for the DisplayLink enabled video outputs. The audio and Ethernet support is provided by native macOS drivers from OS version 10.11.
We have become aware that installing macOS release Version 10.13.4 will cause DisplayLink connected displays to go blank after the OS upgrade, with the current DisplayLink driver [4.1] installed. Functionality such as Ethernet and audio, where implemented, is unaffected. We have alerted Apple to this issue and are working hard to find a resolution. These features continue to work as expected in 10.13.3.
In the meantime, we have a new driver [4.3] that will enable clone mode, but not mirror or extended mode displays in 10.13.4. If you require mirror or extended mode displays, we recommend that you stay on macOS 10.13.3 or earlier at this time.