You might need to set Windows Update to automatically download and work offline mode stuck 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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.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.

• We're working to make it possible to edit shared calendars in Outlook 2016 for Windows.
• 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.
• 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.
• Until you can install the Windows Update fix release, you can set a registry key that will cause Outlook to stop using the local Windows Search service.
• If you typically use an Outlook.com account for email, this issue can occur if there are multiple aliases on the account and the 3rd party email address is the primary alias.
• Many users encounter startup freezes, profile loading loops, and crashes following major Windows patches or Office updates.
• Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.
• Following the above steps—from safe mode diagnostics to repairing data files—will restore functionality in most cases.
• The loading of unregistered MAPI services has been disabled by default to make Outlook more secure.

Outlook Known issues in October 2020 updates

You can also add the secondary connected accounts (Gmail, Yahoo, etc.) in Outlook.com as additional accounts in the Outlook profile. Until you can install the Windows Update fix release, you can 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 troubleshoot Outlook synchronizing folders error message below to indicate it is not using the Windows Search service. 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.

Outlook known issues in the January 2019 updates

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 FixTechGuide mailbox repair steps 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.

Troubleshoot Outlook for Windows issues

Please install the latest updates on your phone to resolve the issue. 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.

Outlook Known issues in March 2025 updates

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).



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. The only other change to the Exchange Server was a certificate update for IIS. This is a standard DigiCert wildcard cert that we have replaced every year with no issues.