Have you already installed macOS Sonoma 14.4? Then you may currently be experiencing problems with linked printers and external screens. Due to an unknown error, in some cases these accessories are no longer recognized by your Mac.
On the Apple Support forum and on Reddit there are numerous posts reporting these problems. The drivers for these components no longer function properly due to an error. This prevents the devices from communicating with macOS. Apple will have to solve this problem with an update.
Printers stop working on Mac
Since macOS 14.4, more and more users have reported that their Mac cannot connect to their printer. This makes it no longer possible to print documents. Unfortunately, removing and re-adding the printer to the Mac does not help.
Due to an error in macOS, the drivers that control the printer can no longer be called up. Unfortunately, we have to wait until Apple comes up with a solution. Not all printers are affected, but some still function properly.
USB hubs from external displays
Another issue introduced by macOS 14.4 is the communication with USB hubs of some external monitors. The update blocks the USB hub functionality of some displays, causing peripherals such as mouse and keyboard connected to the external monitor to stop working.
Apple has yet to acknowledge the problem and release a software update to fix the bug. In the meantime, users have found a workaround. If you are affected by the bug, you can try the following:
- Open  ▸ System Settings
- Go to ‘Privacy and Security’
- Scroll down to ‘Security’
- Click the drop-down menu next to ‘Allow connection to accessory’
- Choose ‘Ask every time’
Now switch off the external display, disconnect it and unplug it from the socket. Restart your Mac, turn your monitor back on and connect it to your Mac. Confirm the link via the pop-up on the screen. Check whether the accessories work again when you use them via the Display.