If you use a third party Mac display, such as DisplayLink or Duet Display products, hold off on updating to macOS 10.13.4. The latest update makes these products useless because of driver issues. These products involve using your iPad as a second screen to your Mac (viaTechRadar).
So far, the products revealed as not working with macOS 10.13.4 include:
- Duet Display
- Air Display
A DisplayLink product manager said that macOS itself is the problem, not DisplayLink itself:
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,” the product manager writes. “If you require mirror or extended mode displays, we recommend that you stay on macOS 10.13.3 at this time.
Some are speculating that the issue lies with Apple’s eGPU technology it added to the operating system. So far it doesn’t sound like it affects displays that connect directly to Macs using mini DisplayPort or Thunderbolt.