Overview

In January 2025, Microsoft addressed a critical issue causing Microsoft 365 applications, including Classic Outlook, to crash on Windows Server 2016 and 2019 systems. The problem stemmed from an Office update that integrated the React Native framework, leading to application crashes within 15 seconds of launch. (bleepingcomputer.com)

Background

React Native is an open-source framework developed by Facebook, enabling developers to build cross-platform applications using JavaScript. Microsoft incorporated React Native into Office 365 to enhance functionality and maintain a consistent user experience across platforms. However, this integration inadvertently caused stability issues on certain Windows Server environments. (petri.com)

Technical Details

The crashes were linked to Office Version 2412 (Build 18324.20168). Users reported that applications like Outlook, Excel, Word, and PowerPoint would terminate unexpectedly shortly after opening. The issue was particularly prevalent among users who had updated their Microsoft 365 apps to this specific version. (bleepingcomputer.com)

Microsoft's Response

Upon identifying the issue, Microsoft released an Office Suite update to rectify the problem. For users with automatic updates enabled via the Office Content Delivery Network (CDN), no action was required. Those managing updates manually were advised to download and deploy the latest update. The rollout commenced on January 16, 2025. (bleepingcomputer.com)

Workaround

For users unable to apply the update immediately, Microsoft provided a workaround to revert to the previous stable version (Version 2411, Build 18227.20162):

  1. Open Command Prompt with administrative privileges.
  2. Execute the following commands:

``INLINECODE0 ``

  1. Disable automatic updates by navigating to File > Office Account > Update Options > Disable Updates.
  2. Set a reminder to re-enable updates on February 11, 2025. (support.microsoft.com)

Implications

This incident underscores the complexities involved in integrating new frameworks into existing software ecosystems. While React Native offers numerous benefits, its incorporation into Office 365 highlighted potential compatibility challenges, especially within server environments. Organizations are reminded of the importance of thorough testing and phased rollouts when implementing significant updates.

Conclusion

Microsoft's prompt response and the provision of both a fix and a workaround demonstrate their commitment to maintaining the stability and reliability of their products. Users are encouraged to ensure their systems are updated to the latest versions to benefit from these resolutions.