After updating Office, you may experience a brief flashing window every hour, which triggers the OfficeBackgroundHandlerRegistration task to start running. 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.

My Outlook 365 won't open after a Windows update yesterday.

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. Note that you can quickly tell how your mail is currently sorted, by the presence of a small triangle on the field headers. Outlook 2016 freezes when you try to preview an Excel file that's attached to an email. This issue affects all Outlook versions on Windows 7, Windows 8, Windows 10.

Outlook Known issues in June 2022 updates

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. In the meantime, please use the workarounds suggested for each issue. 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.

Outlook Known Issues in June 2021 updates

The loading of unregistered MAPI services has been disabled by default to make Outlook more secure. 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. We're working to make it possible to edit shared calendars in Outlook 2016 for Windows. We've run into some issues with the 'New' Outlook this week after 6+ months of usage that other may run into.

Some Web-based Outlook add-ins don't work in when using on premise Exchange 2013

• The platform validates SMTP, IMAP, and POP3 settings against verified databases to identify version mismatches or broken profiles introduced after system updates.
• Outlook 2016 freezes when you try to preview an Excel file that's attached to an email.
• Stay updated, back up regularly, and enjoy uninterrupted productivity in your Outlook workspace.
• If you 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.
• You can also add the secondary connected accounts (Gmail, Yahoo, etc.) in Outlook.com as additional accounts in the Outlook profile.
• Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.
• We're investigating the issue and will update this page when a fix is available.
• 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.

My computer (running Windows 11 Pro) forced an update about two weeks ago. Since the update, my Outlook will not return to "new" Outlook, it deleted my email signature, and is incredibly delayed in getting messages. I am opening the "classic" Outlook app on my computer because the one labeled new seems to not actually be a functioning app (no icon, nothing happens when I click on it). When the Outlook app opens, I can see the 'Try Fix Outlook Not Opening After Windows Update the new Outlook' toggle. The toggle just turns back off and the app does nothing different.

Outlook known issues in the June 2017 security updates

It’s harmless and resolves 30% of stuck startup issues according to Microsoft community reports. Until you can install the Windows Update fix release, you can resolve Outlook not sending emails fast set a registry key 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.

Getting Started Is Easy

Many users encounter startup freezes, profile loading loops, and crashes following major Windows patches or Office updates. Fortunately, most of these errors stem from configuration conflicts, corrupted data files, or outdated components that can be fixed with a few targeted steps. If your Outlook suddenly stopped opening after a Windows update, don’t panic.

Repair Outlook OST File Not Working in Office 365 – Complete Fix (

This ensures Outlook and Windows run the same DLL versions and registry references. Third-party add-ins are among the most common culprits for Exchange connectivity diagnostic Outlook not opening properly. Safe Mode allows you to start Outlook with all extensions temporarily disabled.