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 Most startup failures arise from minor configuration mismatches or outdated components.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

• Find solutions to common problems or get help from a support agent.
• You don't have permission to create an entry in this folder.
• Many users face this frustrating issue after a Windows update or due to corrupted Outlook data files.
• 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.
• When this registry key is set, Outlook will use its own built-in search engine.

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 FixTechGuide support for Office 365 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 repair corrupted OST 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 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

For more information about when builds are available for their respective channels, go to Update history for Microsoft 365. We're investigating the issue and will update this page when a fix is available. MAPI does not validate that a provider's DLL that it is requested to load is registered correctly in MapiSVC.inf or even that it comes from the local machine. This can be exploited by creating a file together with an OLE object in such a way to cause MAPI to load a DLL from a network share when the OLE object is activated. If you're using Outlook 2010, Outlook 2013 or Outlook 2016, uninstall and re-install iCloud to resolve this issue. Here is a comprehensive list of possible causes for the error ‘Outlook inbox not updating’ and how they can affect the working of Outlook.

Step 3: Repair Outlook Data Files

If you've already clicked guide to Office 365 sign-in errors 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

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.





You might need to set Windows Update to automatically download and install recommended updates. Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities. To install the latest Windows and Office updates, click the link below. This often resolves startup errors caused by configuration issues.

Note that you can quickly tell how your mail is currently sorted, by the presence of a small triangle on the field headers. Another options is to use the Filter Email button on the ribbon. 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.