Microsoft Outlook is excellent full-featured, powerful, and dependable email software. However, you can run into problems with Outlook not loading or opening at times. When you choose the Microsoft Outlook program from the Start menu or a shortcut icon, it won’t depend on the issue you are having and the version of Microsoft Outlook you are using. Ensure that Allow Apps to Access Your Calendar is enabled and that Mail and Calendar are both set to allow access to the Calendar. Check for updates: A recent update may contain a fix for the issue of outlook not starting. Even if you can’t launch outlook, check for and install any available updates. After that, go to Help and see if there are any updates. Then select update to download and install all available updates, rebuild the Outlook database: The problem of outlook not opening on a Mac could be solved by using the Microsoft program to rebuild a broken database.