We are 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 are releasing 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 at this time.
We understand that this loss of functionality on OS upgrade is potentially disruptive for our users and customers. Please be assured that this issue has the highest business priority in DisplayLink. We thank you for your patience and will provide an update on this situation, as soon as we have further information to share.
This is a popular company with displays this must be a huge disruption to anyone using a mac. Luckly the software still works with Windows, ChromeOS, Android and Ubuntu.