Outlook/Exchange Calendar won't re-add, error 3

I was having sync issues both with Gmail and my Exchange calendar in the Calendar app (Version 16.0 (3036.4.14), Tahoe 26.6.2) and following common recommendations, deleted my Exchange account to re-install it. Except, it won't reinstall.

I go through the Exchange log-in screen, 2FA through Authenticator, and ultimately end up with an error, The operation couldn't be completed. (com.apple.accounts error 3.) Google tells me this a problem with EWS being phased out, but I haven't found any solutions.

I seem to be now stuck with no way to put my work calendar into my computer's app. My iPhone still has the account and syncs fine. Looking for tips on how to get my Outlook cal, iCal, and multiple Google Cals all in one place again.

Posted on Oct 29, 2026 8:56 AM

1 reply

razmee209

Level 10 (205,348 points)

Oct 29, 2026 1:37 PM in response to argumentative_ketchup

argumentative_ketchup wrote:

I was having sync issues both with Gmail and my Exchange calendar in the Calendar app (Version 16.0 (3036.4.14), Tahoe 26.6.2) and following common recommendations, deleted my Exchange account to re-install it. Except, it won't reinstall.

I go through the Exchange log-in screen, 2FA through Authenticator, and ultimately end up with an error, The operation couldn't be completed. (com.apple.accounts error 3.) Google tells me this a problem with EWS being phased out, but I haven't found any solutions.

I seem to be now stuck with no way to put my work calendar into my computer's app. My iPhone still has the account and syncs fine. Looking for tips on how to get my Outlook cal, iCal, and multiple Google Cals all in one place again.

Since it is a work calendar have you reported the issue to your IT administrator?