Some multi-touch touch devices recognise they are plugged into non Windows systems and switch modes so that they present themselves as a HID mouse device to allow the native HID driver to work with the device in single touch mouse emulation mode.

When UPDD is installed it loads a kernel extension file that is used to prevent the native HID class driver taking control, leaving UPDD to gain access to the device.

UPDD uses Windows USB requests to switch the touch device back into multi-touch mode, hence multi-touch functionality is restored.

However, in some cases, when uninstalling UPDD it has been reported that single touch mouse emulation not longer works and the device cannot function in single touch mode.

It was discovered that although the uninstaller issues a command to uninstall the file it was not removed. This was reported to be the case in macOS 10.15.

The kext file resides in location /Library/Extensions and is called tbupddmxhid.kext

Manually deleting this file should resolve the issue.

It was also observed that just deleting the file did not always resolve due to cached copies

sudo kextcache --clear-staging
sudo kextcache -i /

Reboot for the cache changes to take effect.

We have since changed the uninstaller (Nov 2020) to use another method to delete this file and clear cache and this issue now appears to be resolved.