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 Most startup failures arise from minor configuration mismatches or outdated components.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"?

• It’s harmless and resolves 30% of stuck startup issues according to Microsoft community reports.
• To learn more about how to send us feedback, please see How do I give feedback on Microsoft Office.
• FixTechGuide’s free email diagnostic tools automate error detection by scanning your configuration files, registry entries, and mail protocols.
• The built-in search will display the message below to indicate it is not using the Windows Search service.
• By the end, you’ll know exactly how to restore your Outlook and prevent future errors.
• Online Repair reinstalls Outlook components while preserving your data, resolving DLL and registry mismatches that prevent startup.
• The issues documented in this section have been reported after installing the recent updates listed below.
• We're investigating the issues and will update this page when a fix is available.

There is currently no option to revert to the prior behavior, but we would love to hear your feedback to help us with future designs. To learn more about how to send us feedback, please see How do I give feedback on Microsoft Office. To access the filtering options faster, add them to your online Outlook email repair utility Quick Access Toolbar.

Outlook known issues in the Jan 2018 updates

This issue affects all Outlook versions on Windows 7, Windows 8, Windows 10. If you Outlook Not Sending or Receiving Email 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 things we 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.



If you manually type in the secondary connected account email address in the "From" field, the email is sent as "On behalf of" your primary Outlook.com account. Please install the latest updates on your phone to resolve the issue. Outlook forwards meeting invitations to other attendees without anyone actually sending an update or forwarding an invite. This happens to accounts that are configured in the fix Outlook after Windows update issues iOS Mail app. The issues documented in this section have been reported after installing the recent updates listed below. We're investigating the issues and will update this page when a fix is available.

Windows Command prompt running OfficeBackgroundHandlerRegistration task flashes every hour

This occurs because custom form script is now disabled by default. Are you struggling to open Microsoft Outlook on your Windows 11 PC? Many users face this frustrating issue after a Windows update or due to corrupted Outlook data files.





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.