mcaffe internet security uninstaller quit unexpectedly

Boot your Mac into Safe-Mode and run the McAfee uninstaller once the Mac has booted fully into Safe-Mode.

This Apple document lists the key combos to boot your Mac into Safe-Mode:

https://support.apple.com/en-gb/HT201255

This Apple document describes Safe-Mode in more detail:

https://support.apple.com/en-gb/HT201262

A Safe-Mode boot may take a long time, up to ten minutes before your desktop is reached and while in Safe-Mode the system may appear very "laggy" do not be concerned, this is normal.

If this is successful then exit Safe-Mode with a restart and the Mac will boot into normal mode.

If the above is unsuccessful then contact McAfee support for specific help with their products.

HTH

Will.

Do not use non-Apple "internet security" products on Macs.

Effective defenses against malware and other threats - Apple Community