Deletes font caches, kernel cache, and other system cache files.Prevents Startup Items and Login Items from opening automatically.

Verifies your startup disk and attempts to repair directory issues, if needed.Next, use safe mode to start up your Mac as it does the following things: If we understand correctly, you are unable to use your Kensington trackball with your Mac as expected, as the KensingtonWorks software isn't working as expected on your Mac. Thanks for that info and for choosing the Apple Support Communities. It says 'Select 'Quit Now' to activate the setting,' but I can't find 'Quit Now.' I tried every kind of quitting I could think of and it doesn't keep the window from popping up upon startup, so, I just close it. However - even though the mouse is working fine, upon start up, a KensingtonWorks window pops up saying it needs access to my Mac and wants me to open Security & Privacy and go through all the steps I've done already. I clicked on that, followed whatever needed to be checked (can't remember), and the mouse regained functionality. In addition to that, still in Security and Privacy under General, 'Allowed apps downloaded from:' there was a message that software needed my attention. Each time I was checking the Security & Privacy of System Preferences, making sure Accessibility and Input Monitoring was checked. I followed along from discussions here and uninstalled Kensington Works first, then tried it again. The cursor would work, but my customized buttons wouldn't - double click for example and the scrolling was bad. I downloaded the new driver from the site and installed it, twice. I just moved to Big Sur with an old Kensington trackball.

K64325 kensington mouse driver