Third-party add-ins are among the most common culprits for Outlook not opening properly. Safe Mode allows you to start Outlook with all extensions temporarily disabled. You don't have permission to create an entry in this folder. Right-click the folder, and then click Properties to check your permissions for the folder. See the folder owner or your administrator to change your permissions. Currently, you can't use Outlook on Windows to edit calendars that are shared with your Outlook.com account, even if you've reconnected your Outlook.com account to Outlook.

Disable Hardware Graphics Acceleration

If your Outlook suddenly stopped opening after a Windows update, don’t panic. Most startup failures arise from minor configuration mismatches or outdated components. Following the above steps—from safe mode diagnostics to repairing data files—will restore functionality in most cases.

Do you see the message "This set of folders could not be opened"?

• Once the scan completes, reopen Outlook and check if the issue is resolved.
• You may notice that All, Unread , Mentioned and other sort and filtering options, such as By date, and Newest are missing in Outlook above your email list.
• Outlook not opening on Windows 11 is usually caused by corrupted files or conflicting add-ins, but with the above methods, you can easily fix it.
• See the folder owner or your administrator to change your permissions.
• Occasionally, classic Outlook tries to run a process in the background.
• Please install the Windows 10 Fall Creators Update to fix this issue.
• Right-click the folder, and then click Properties to check your permissions for the folder.
• To access the calendar shared with your Microsoft 365 for business account, you'll need to accept the invitation from Outlook on the web, iOS, or Android.

In this guide, FixTechGuide explains the top causes and provides simple step-by-step solutions to help you fix Outlook not opening on Windows 11 quickly. Until you can install the Windows Update fix release, you can set a registry key Fix Outlook and Office365 Sync Issues that will cause Outlook to stop using the local Windows Search service. When this registry key is set, Outlook will use its own built-in search engine. The built-in search will display the message below to indicate it is not using the Windows Search service.

Outlook known issues in the Jan 2018 updates

This issue affects all Outlook versions on Windows 7, Windows 8, Windows 10. If you disable faulty add-ins in Outlook can't open Outlook, or Outlook disappears or crashes, one of your add-ins may be to blame or you may need to update Outlook. If you are having problems with Outlook, there are a few thingswe can help with to get you back to sending and receiving your email. Sometimes, aggressive antivirus programs block Outlook’s execution. If Outlook opens, whitelist the Outlook process in your antivirus settings. This ensures Outlook and Windows run the same DLL versions and registry references.

Outlook known issues in the November 2019 updates

Once the scan completes, reopen Outlook and check if the issue is resolved. Go to File → Options → Add-ins → disable all add-ins, then re-enable them one by one to find the faulty one.

Step 3: Repair Outlook Data Files

If you've already clicked how to Fix Outlook not opening today the Accept button in Outlook 2016, you won't be able to re-accept the invitation from another Outlook application. The person who sent you the invitation will need to remove your permissions and then send a new invitation. This command deletes the custom folder views, restoring default configurations. It’s harmless and resolves 30% of stuck startup issues according to Microsoft community reports.

Windows Command prompt running OfficeBackgroundHandlerRegistration task flashes every hour

We're working to make it possible to edit shared calendars in Outlook 2016 for Windows. After installing the September Public Update, Outlook 2007 displays mixed languages in the user interface. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. The folder may have been deleted or the server where the folder is stored may be unavailable. You don't have appropriate permission to perform this operation.

Outlook Known issues in February 2024 updates

By the end, you’ll know exactly how to restore your Outlook and prevent future errors. If your Microsoft Outlook won’t open after a recent Windows update, you’re not alone. Many users encounter startup freezes, profile loading loops, and crashes following major Windows patches or Office updates.

FixTechGuide’s free email diagnostic tools automate error detection by scanning your configuration files, registry entries, and mail protocols. The platform validates SMTP, IMAP, and POP3 settings against verified databases to identify version mismatches or broken profiles introduced after system updates. You can also add the secondary connected accounts (Gmail, Yahoo, etc.) in Outlook.com as additional accounts in the Outlook profile. To access the calendar shared with your Microsoft 365 for business account, you'll need to accept the invitation from Outlook on the web, iOS, or Android.