No longer possible to create calendars on my Mac
I recently had to sign out of iCloud on my MacBook Pro. This created a mess with my calendars because some of my calendars were on iCloud while some others were on my Mac. Now it is no longer possible to have local calendars. The option to create a calendar "on my Mac" has disappeared. I did not have this problem in El Capitan. I'm guessing this is related to my upgrade to Mojave. Is there a way to fix this problem?
MacBook Pro 15", macOS 10.14