Apr 30, 2020 · Click File option and then select Options. Go to Advanced tab and check the option Enable Troubleshooting logging. Restart the Outlook and go to the temporary folder (%temp%). Here, check the recent logs which may show possible errors related to the shared mailbox. Sep 18, 2013 · When a service account is hidden from the GAL, the only way to subscribe to its calendar is to use the Add calendar option within the email invitation that is sent as a result of the service account sharing it's calendar. The Add calendar option does not work in local Outlook clients. When users attempt to subscribe to the calendar, the button ...