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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.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 learn more about how to send us feedback, please see How do I give feedback on Microsoft Office.
• 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.
• 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.
• We're investigating the issues and will update this page when a fix is available.

Outlook Known issues in October 2020 updates

After installing the September Public Update, Outlook 2007 displays mixed languages in the user interface. If you are having problems with Outlook, modern authentication troubleshooting there are a few things we can help with to get you back to sending and receiving your email. Find solutions to common problems or get help from a support agent. Please install the Windows 10 Fall Creators Update to fix this issue.

Outlook known issues in the January 2019 updates

Auto-archive, sending and receiving a very large attachment, or running reset cached Exchange mode some of the other mailbox tools can all be done in the background. Check the status bar at the bottom of the screen to see if another process is running. If so, wait a short time (usually two or three minutes) to see if Outlook starts working again. 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.

Troubleshoot Outlook for Windows issues

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 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.



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.