This is an extremely rare case, and can occur due to the following reasons:
- A newly installed Mac OS X update is not compatible with a preexisting DL driver
- A newly installed DL driver is not compatible with the installed Mac OS X version
- A third party kernel extension or application loaded at boot is not compatible with the DL driver
In these cases the solution is to shut down the computer by pressing the power button for more than 5 seconds. During reboot hold down the shift key for approximately a minute, this will invoke a safe boot. A safe boot will take considerably longer than usual.
No third party kernel extension or application will be loaded during safe boot and automatic login will be disabled, so the user will have to log in to their account.
Once logged in, the user should run the DisplayLink uninstaller, and reboot. After reboot the user should then try to install the latest DisplayLink driver, or third party kernel extension, which should hopefiuly resolve this issue.