A puzzling Oauth related message, and how I dealt with it: (irc cut and past, hence the weird looking style ;) )
Rebooting with akonadi 18.08 (debian), I've got that message "akonadi resources for google services". For a gmail address of mine. I'm wondering what it can be. So I checked "cancel" and as a consequence it said my gmail account is broken. I reconfigured my account using imap.googlemail.com instead of imap.gmail.com; I hope it will suffice. OK, it did work. Beware it also "changed" my password for a very long "password", so you'll have to enter your password back. The place I did the changes is: Kmail settings > Accounts > Receiving > There I selected the faulty gmail account; And I did "modify"; Changed imap.gmail.com to imap.googlemail.com; Fixed my password; And there it is. Thanks, Chris