On April 10, 2025, Microsoft issued an emergency update, KB5002623, to address critical issues causing Office 2016 applications—specifically Word, Excel, and Outlook—to become unresponsive following the installation of a prior update, KB5002700. This problem predominantly affects MSI-based editions of Office 2016, leaving Click-to-Run versions like Microsoft 365 Home subscriptions unaffected.
Details of the Issue
The root cause of these crashes has been traced to modifications in the Mso20win32client.dll file, which was altered in the previous update. The updated versions of this file (16.0.5495.1002) for both 32-bit and 64-bit systems were compiled on March 22, 2025, indicating that Microsoft has been working on this fix for several weeks.
Steps to Apply the Update
To fully restore functionality to Office 2016, users must install both KB5002700 and the new KB5002623 updates. The emergency patch is available for manual download from the Microsoft Download Center. Users should determine their Office installation’s architecture (32-bit or 64-bit) to download the correct version.
Installation Instructions:
1. Download the Update:
– Visit the Microsoft Download Center.
– Select the appropriate version (32-bit or 64-bit) based on your Office installation.
2. Install the Update:
– Run the downloaded file and follow the on-screen instructions.
– A system restart may be required to complete the installation.
For IT Administrators:
Organizations can deploy this update across multiple systems using enterprise management tools like System Center Configuration Manager. The update files have been thoroughly scanned for viruses and are stored on secure servers to prevent unauthorized modifications.
Uninstallation Process:
If issues persist after installation, users can uninstall the update:
1. Navigate to the Control Panel.
2. Search for Installed Updates.
3. Locate KB5002623, select it, and click Uninstall.
Conclusion
Microsoft’s prompt response with the KB5002623 update aims to mitigate the disruptions caused by the previous patch. Users and organizations are encouraged to apply this update promptly to ensure the stability and functionality of Office 2016 applications.
