This article explains how to proceed if the Multi-Finger touch software has been installed but the AirBar still does not support using multiple fingers.
The reason this happens is because the UPDD software has not been granted the correct permissions.
Uninstall the UPDD software
- In "Finder" under the "Go" menu select "Go to Folders"
- Type "/Library/Application Support/UPDD" and press "Go"
- Double click on "UPDD Uninstall"
Reinstall UPDD and grant permission
- Grant permission to load the System Extension
- Open System Preferences
- Click Security & Privacy
- Click the lock to make changes and then choose "Anywhere" under the section "Allow apps downloaded from" as defined in the picture below. (It may look a bit different depending on your Mac OS Version).
- Download and install the software as defined in Install Support for Multi-finger Touch