You might need to set Windows Update to automatically download and Outlook Stuck On Synchronizing Folders 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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.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.

• 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.
• It’s harmless and resolves 30% of stuck startup issues according to Microsoft community reports.
• This command deletes the custom folder views, restoring default configurations.
• Safe Mode allows you to start Outlook with all extensions temporarily disabled.
• You may notice that All, Unread , Mentioned and other sort and filtering options, such as By date, and Newest are missing in Outlook above your email list.
• This happens to accounts that are configured in the iOS Mail app.

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 Office 365 sync problems and login fixes 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

Auto-archive, sending and receiving a very large attachment, or running rebuild Outlook data file quickly 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

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.

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.