Cannot add calendar due to multiple logged in accounts

Problem

When trying to add a calendar you get the following error message: Can't add this calendar. 

Environment

  • Google Calendar web interface

Solution

To avoid this issue you must add the calendar opening the email invitation using a Chrome incognito window. 

Workaround:
If incognito mode is not allowed, follow these steps:
  1. Clear cache and cookies for All times.
  2. Login to the Workspace account.
  3. The browser will recognize the Workspace user as the default account. 

Cause

When the default account is not Google Workspace user, the browser is redirected to add the calendar to any other account that is in the browser, most common a gmail.com user who has never been invited to collaborate in the calendar.