Microsoft has issued an emergency patch addressing widespread crashes in Office 2016 applications following a problematic update.
The fix, identified as KB5002623 and released on April 10, 2025, resolves critical issues that caused Microsoft Word, Excel, and Outlook to stop responding after the installation of a previous update.
According to Microsoft’s support documentation, this emergency fix specifically addresses problems introduced by the earlier update KB5002700.
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The issue primarily impacts MSI-based editions of Office 2016 and does not affect Click-to-Run editions such as Microsoft 365 Home subscriptions.
Improvements and Fixes
“This update fixes the known issue in KB 5002700 that causes Microsoft Word, Microsoft Excel, and Microsoft Outlook to stop responding,” Microsoft stated in the release notes.
The company emphasizes that users must have both updates—KB 5002700 and KB5002623—installed to fully restore Office 2016 functionality.
Technical analysis reveals the root cause is related to the Mso20win32client.dll file, which received modifications in the latest patch.
The updated file versions (16.0.5495.1002) for both x86 and x64 architectures were compiled on March 22, 2025, suggesting Microsoft has been developing this fix for several weeks.
For affected users, Microsoft has made the update available for manual download from the Microsoft Download Center.
The patch comes in both 32-bit and 64-bit versions, requiring users to identify which architecture their Office installation uses before downloading the appropriate file.
How to Download and Install the Update
“Organizations relying on Office 2016 should prioritize this update immediately,” said Thomas Reynolds, IT infrastructure analyst.
“The widespread nature of these crashes has significantly impacted productivity for businesses still using this version of Office.”
Microsoft confirms all update files have undergone thorough virus scanning using current detection software and are stored on security-enhanced servers to prevent unauthorized modifications. Users will likely need to restart their computers after applying the update.
For IT professionals needing to deploy the fix across multiple systems, the update can be distributed through standard enterprise management tools like System Center Configuration Manager.
The technical documentation reveals file sizes of 3,181,792 bytes for the x64 version and 1,940,160 bytes for the x86 version of the critical Mso20win32client.dll file.
Users experiencing continued issues after installation can uninstall the update through the Control Panel.
On Windows 10 and Windows 11, this requires navigating to “Start” and entering “Control Panel,” then searching for “Installed Updates,” selecting KB5002623, and clicking “Uninstall.”
Industry experts note this is not the first emergency update Microsoft has issued for Office products this year.
Microsoft has not indicated whether additional fixes might be needed but recommends users contact Microsoft Support if problems persist after installing both required updates.
Organizations are advised to save all work before initiating the installation process and consider testing in controlled environments before wide deployment.
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