Problem

Performing free/busy requests to Google failed with the error ‘Google.Apis.Requests.RequestError Invalid Credentials [401] Errors [ Message[Invalid Credentials] Location[Authorization – header] Reason[authError] Domain[global] ] ‘.

Cause

The login filled in the field Free/busy User Login is not valid

Resolution

Check if your user have:

  1. A valid account (no issue with password expired, or inactive account)
  2. A valid access to use G Suite Calendar