I thought I had solved the issue with OneDrive, but NO. I was wrong. It did slow the number of crashes but now it has become more erratic than before. Some things seem to be consistent, though: TimeMachine starts failing to back up Office365 apps begin to crash (and this is due to problems accessing Profiles) Memory hogs say apps should be closed (even though they are not clogging - as seen on Activity Monitor). When trying to reboot before it crashes, computer closes all apps but won't reboot - it gets stuck "after" closing the Finder So you force shut down. When you restart the computer, all your personal logins on browsers are gone, all your Finder Windows are closed (Safari even closes all open windows - and returns to older instances, not the one before restart) and Office apps are able to reopen again. OneDrive may or may not be open. So something happens in the library since it destroys part of the cache and personal data saved on browser.