Software & Apps MS Office What To Do When Microsoft Outlook Won't Open Troubleshooting Microsoft's email application by Tricia Goss Writer Tricia Goss has been a writer and editor for 10+ years. She's written tips and tutorials for Microsoft Office applications and other sites. our editorial process Facebook Twitter LinkedIn Tricia Goss Updated on September 11, 2020 reviewed by Ryan Perian Lifewire Tech Review Board Member Ryan Perian is a certified IT specialist who holds numerous IT certifications and has 12+ years' experience working in the IT industry support and management positions. our review board Article reviewed on Feb 09, 2020 Ryan Perian MS Office Outlook Word Excel Powerpoint Tweet Share Email When you select the Microsoft Outlook program from the Start menu or a shortcut icon, but Outlook won't open, the right fix depends on what you experience as well as the version of Microsoft Outlook that is installed. Lifewire / Miguel Co Causes of Outlook Not Opening Several issues could cause Outlook to open incorrectly or not at all. Some common culprits include: Problematic add-ins.Damaged files.A corrupted profile.Navigation pane issues. How To Fix Outlook Not Opening in Windows If you use Outlook on a Windows computer and Outlook doesn't open or opens with problems, try these troubleshooting steps in the order presented here, from simple to more complicated. If you use the cloud-based Microsoft 365 on a PC or a Mac, the automated Support and Recovery Assistant tool can diagnose and fix many issues, including the problem of Microsoft Outlook not starting. Open Outlook in Safe Mode. If Outlook opens as expected in Safe Mode, the issue is likely an add-in or toolbar extension. Disable add-ins. One or more add-ins could be conflicting with Outlook and cause the problem. Disable all add-ins and see if this resolves the issue. Select File > Options > Add-ins.In the Manage section, select Go.Clear the check boxes next to the add-ins you want to disable.Select OK. Repair Outlook. The Outlook application may be damaged. Use the built-in Microsoft Office repair utility to fix it. Close all Office applications.Go to Start > Control Panel.Select Category View.In the Programs section, select Uninstall a Program.Right-click Microsoft Office and choose Change.Select Online Repair or Repair. Choose Yes if a user account control prompt appears.Restart Outlook after the process completes. Repair your Outlook profile. Outlook profiles can become corrupted, causing all sorts of problems, including Outlook not opening. Select File > Account Settings > Account Settings.Go to the Email tab.Choose Repair to open the Repair wizard (this option is not available for Outlook Exchange accounts).Follow the prompts to complete the wizard and restart Outlook. Repair Outlook data files. If Outlook still doesn't open, use the Inbox Repair tool to find and possibly fix the problem. Exit Outlook.Download and open the Inbox Repair Tool from Microsoft.Select Browse and navigate to your personal folders (.pst) file, then select Start.Choose Repair if the scan finds errors.When the repair is complete, restart Outlook. Reset the navigation pane. A startup issue with the navigation pane can prevent Outlook from opening correctly. Resetting the navigation pane might resolve the issue. Exit Outlook. Go to Start > Run or press Windows Key+R.Type or paste outlook.exe /resetnavpane and select OK.Open Outlook. The navigation pane will be reset. How To Fix Outlook Not Opening in Mac The following troubleshooting techniques apply to Outlook 2016 for Mac and Outlook 2011 for Mac. Check for updates. A recent update could include a fix for the problem of not being able to start Outlook. Check for and install any available updates, even if you cannot open Outlook. Select Help > Check for Updates. Choose Update to download and install all available updates. Rebuild the Outlook database. Using the Microsoft utility to rebuild a corrupted database might solve the problem of Outlook not opening on a Mac. If you have a Microsoft Exchange account, rebuilding the database deletes any information that isn't synced with the server. Back up any Outlook data stored only on your computer before you rebuild the database. Exit all Office applications. Press the Option key and select the Outlook icon in the Dock to open the Microsoft Database Utility.Select the identity of the database you want to rebuild.Choose Rebuild.When the process is complete, restart Outlook.