You might need to set Windows Update to automatically download and FixTechGuide support for Office 365 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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.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.

• If you can't choose any of the menu options, type inside an email message, calendar event, or contact, Outlook may have frozen.
• 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.
• This solution prevents display rendering errors that occur after driver or DirectX updates.
• Third-party add-ins are among the most common culprits for Outlook not opening properly.
• If you're using Outlook 2010, Outlook 2013 or Outlook 2016, uninstall and re-install iCloud to resolve this issue.
• For more information about when builds are available for their respective channels, go to Update history for Microsoft 365.
• 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.
• We're investigating the issues and will update this page when a fix is available.

Outlook Known issues in October 2020 updates

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. Right-click the folder, and then click Properties to check your permissions for the folder. See credential loop in Microsoft 365 the folder owner or your administrator to change your permissions. 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.

Outlook known issues in the January 2019 updates

Many users encounter startup freezes, profile loading loops, and crashes following major Windows patches or Office updates. Fortunately, most of Outlook Login Issues Troubleshooting these errors stem from configuration conflicts, corrupted data files, or outdated components that can be fixed with a few targeted steps. By the end, you’ll know exactly how to restore your Outlook and prevent future errors. If your Outlook suddenly stopped opening after a Windows update, don’t panic.

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

If you've already clicked 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. 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.

Outlook issues after connecting Outlook to Outlook.com

When the Outlook app opens, I can see the 'Try the new Outlook' toggle. The toggle just turns back off and the app does nothing different. I saw a reply to an issue similar to mine that mentioned going to the Registry Editor and followed instructions outlined in that message but nothing changed. If your Microsoft Outlook won’t open after a recent Windows update, you’re not alone.