You might need to set Windows Update to automatically download and Credential loop In microsoft 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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.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.

• By the end, you’ll know exactly how to restore your Outlook and prevent future errors.
• 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.
• 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 mailbox not updating on IMAP 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of Office 365 sync problems and login fixes these errors stem from configuration conflicts, corrupted data files, or outdated components that can be fixed with a few targeted steps.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

Stay updated, back up regularly, and enjoy uninterrupted productivity in your Outlook workspace. Online Repair reinstalls Outlook components while preserving your data, resolving DLL and registry mismatches that prevent startup. This process checks for structural issues and automatically fixes them. Occasionally, classic Outlook tries to run a process in the background.



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. If you can't choose any of the menu options, type inside an email message, calendar event, or contact, Outlook may have frozen. There are three steps you can take to try to get Outlook working again.