Microsoft shares temp fix for Outlook crashing when writing emails

Microsoft has shared a temporary fix for a known issue that causes classic Outlook to crash when writing, replying to, or forwarding an email.

These problems appear after updating Outlook for Microsoft 365, Outlook 2021, Outlook 2019, or Outlook 2016 to Version 2412 (Build 18324.20168), released on January 7, and will trigger “0xc0000005” exception codes.

“You can confirm if this is the issue by looking at the Windows Event Viewer Application Log for crash Event 1000 or Event 1001, and the following event details,” the company says in a recently published support document.

Microsoft says the Outlook team has already found a fix for this bug, which will be pushed to customers in the Current Channel next week, on January 28, with Version 2501 Build 18429.20000.

However, until the fix rolls out to affected customers, the company offers a temporary solution to work around the issue. This workaround requires those impacted to revert Outlook to version 2411 (Build 18227.20162), which isn’t affected by this bug.

To do that, search for ‘Command Prompt’ in the Windows search box, right-click the ‘Command Prompt’ icon, and click ‘Run as administrator.’

Next, paste the following commands in the Command Prompt window that shows up and hit Enter after each:

cd %programfiles%\Common Files\Microsoft Shared\ClickToRun
officec2rclient.exe /update user updatetoversion=16.0.18227.20162

Last week, Microsoft rolled out a fix for another known issue that was causing Microsoft 365 applications and Classic Outlook to crash on Windows Server 2016 or Windows Server 2019 systems.

In early January, it announced that it would automatically install the new Outlook email client on Windows 10 systems, starting with the February 2025 security update.

In recent months, Redmond also shared temporary fixes for other known Outlook issues, including one that caused Outlook to crash after opening and another that triggered Gmail sign-in issues for classic Outlook users