Microsoft says Outlook on the desktop is down due to some "recent updates" [Update]

Microsoft released its Patch Tuesday set of updates to all supported versions of Windows. The update brought with it a few fixes for Windows 10 version 2004’s known issues, such as the random reboot problem caused by the Local Security Authority Subsystem Service (LSASS) failures. Now, users have begun reporting that the latest updates either to the OS or the Office suite of apps are causing Outlook on the desktop to crash.

Users began posting about the issue on Microsoft’s Tech Community forums stating that the mail client fails to open and is stuck at the “starting” screen. The Office 365 Service health portal confirms the outage, adding that the “recently deployed updates are the likely source of the problem”. The company adds that it is investigating the issue to pinpoint the exact cause of the problem. The post also confirms that the issue does not affect Outlook.com or the Android version of the app. Business users can look for additional information in the admin center under ‘EX218604’ and 'OL218603', the firm says.

Other reports suggest that the tool fails with the exception code ‘0xc0000005’, and the only workaround is to roll back to a previous version of Outlook on Windows 10. Alternatively, users that are heavily impacted due to this issue can also try to uninstall the latest cumulative update by heading into Settings > Update & Security > Windows Update > View update history > Uninstall Updates to check if that helps. You can head here to see the exact KB article that was released yesterday for your version of Windows 10.

We will keep an eye on the service health dashboard and will update the article with further updates from the Redmond giant when received.

Update: Microsoft has updated the 'Service health' dashboard stating that the company has identified the cause of the issue and is "applying" a fix. However, it adds that the deployment may take up to a few hours until it reaches all affected users. The company has not provided any further specifics of what the fix is and how it is being applied.

Update 2: Microsoft has noted that the fix has been applied to all environments, adding that "users may need to restart their Outlook client for the fix to take effect".