Hi Kyi, Three suggestions for the current issue. 1. Check whether it’s working in Edge/Chrome. We find you are using IE 11 to work on the configuration, which is no longer supported. 2. You may upgrade your D365 environment to the latest version of v9.1.6 to get better experience. support.microsoft.com/…/service-update-1-6-for-microsoft-dynamics-crm-on-premises-9-1-8a8401c0-b8c8-4288-8c01-59d15692f2ed 3. You may save the profile by using Ctrl + S. You may test enable directly from mailbox configuration.