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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

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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.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. Please install the latest updates on your phone to resolve the issue.

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

Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.You might need to set Windows Update to automatically download and install recommended updates.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.The issues documented in this section have been reported after installing the recent updates listed below.Most startup failures arise from minor configuration mismatches or outdated components.We've run into some issues with the 'New' Outlook this week after 6+ months of usage that other may run into.By the end, you’ll know exactly how to restore your Outlook and prevent future errors.

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 and Office 365 Errors 2025 the new Outlook' toggle. The toggle just turns back off and the app does nothing different.

This occurs because custom form script is now disabled by default. For persistent issues, use FixTechGuide’s automated tools to perform deep diagnostics and security checks. Stay updated, back up regularly, and enjoy uninterrupted productivity in your Outlook workspace. Online Repair reinstalls Outlook Fix Outlook Not Opening After Windows Update components while preserving your data, resolving DLL and registry mismatches that prevent startup. This process checks for structural issues and automatically fixes them.

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.

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