
Microsoft has identified and provided a temporary solution for a critical issue causing Outlook crashes during email composition, replies, and forwards. The problem affects users who updated to Version 2412 (Build 18324.20168) of Outlook for Microsoft 365, Outlook 2021, 2019, and 2016, released on January 7.
The issue manifests as crashes with “0xc0000005” exception codes, identifiable through Windows Event Viewer’s Application Log under Events 1000 or 1001.
While a permanent fix is scheduled for release on January 28 with Version 2501 Build 18429.20000, users can implement the following temporary solution:
1. Open Command Prompt as administrator
2. Navigate to: %programfiles%\Common Files\Microsoft Shared\ClickToRun
3. Execute: officec2rclient.exe /update user updatetoversion=16.0.18227.20162
This workaround reverts Outlook to version 2411 (Build 18227.20162), which operates without the crash issue.
Microsoft has also addressed other recent Outlook-related issues, including crashes on Windows Server 2016/2019 systems and Gmail sign-in problems. The company plans to automatically deploy the new Outlook client on Windows 10 systems with the February 2025 security update.