Mac calendar app (iCal) displays error message "server responded with an error" After upgrading to Mojave, the mac calendar app displays the following error when starting the app.

"server responded with an error"

Is this a problem with Mojave and the gmail server? The error message does not give any further details on the cause of the error.

When I use the mac email app, everything works as it should with receiving and sending emails through gmail.

The attached screen shot shows the error in detail.
Try following sequence.
In System Preferences, Internet Accounts, deselect all Calendars to stop the sync.
Wait for a while for the process to stop.
Than click on the &quot;Revert to Server&quot;

Re enable Calendars.