# Microsoft Resolves Recurring Excel 2016 Copy-Paste Bug A persistent software glitch in Excel 2016 returns after security updates. - **Source:** [The Register](https://www.theregister.com) - **Published:** 2026-11-05 - **Topic:** [technology](https://brifing.si/c/technology) - **Original article:** - **On Brifing:** https://brifing.si/s/0928a099-34f6-41ef-ab48-ba2442d2459a ## Recurring Software Failure Microsoft has released a new build for Excel 2016, version 16.0.5574.1006, to address a recurring copy-paste bug. The issue initially appeared in September, was resolved, and then resurfaced following the October security update. This silent failure prevented users from pasting content into cells, regardless of repeated keyboard commands or system restarts. ## Conditional Formatting Conflict The technical root of this specific failure involves workbooks containing conditional formatting. When these specific formatting rules are applied, the paste operation fails to execute properly. Microsoft confirmed that the latest build specifically targets this interaction, ensuring that data transfer remains functional even when complex cell formatting is present in the document. ## Update Deployment Issues The bug was reintroduced via the KB5002934 security update, which was intended to patch remote code execution and information disclosure vulnerabilities. While the update successfully addressed these security concerns, it inadvertently broke the core copy-paste functionality. Users who rolled back the patch found temporary relief until Windows Update automatically reapplied the update. ## Impact on Workstations Corporate environments reported widespread issues across multiple workstations after the October update was installed. System administrators expressed frustration, noting that the bug was identical to the one supposedly resolved in mid-September. The recurrence caused significant workflow disruptions for teams relying on Excel for data management, highlighting the fragility of legacy software updates. ## Scope of the Glitch The problem is strictly limited to Excel 2016 and is not a broader failure of the Windows security update architecture. It originated from an Excel-specific update delivered through the Windows Update channel. Because the issue was isolated to this version, other modern iterations of Microsoft Excel remained unaffected by the paste failure. ## Lack of Transparency Microsoft has not provided a detailed explanation regarding how the bug was reintroduced into the software build. The company simply acknowledged the failure in the release notes for the new build. This lack of communication regarding the regression process has left many users questioning the quality assurance procedures currently governing legacy software maintenance. ## Historical Software Context Excel has a long history of hidden features and complex codebases, dating back to the Hall of Tortured Souls mini-game in Excel 95. While modern updates focus on security, the complexity of maintaining legacy software like Excel 2016 often leads to unexpected regressions when patches interact with older, deeply embedded formatting functions. ## Current Status and Outlook The latest build, 16.0.5574.1006, appears to have successfully resolved the copy-paste issue for the second time. Users are advised to update their software to this specific build to restore functionality. Moving forward, the incident serves as a reminder of the challenges involved in patching older software without disrupting existing user workflows. ## Sources covering this story - https://www.theregister.com/software/2026/11/05/microsoft-fixed-excel-2016-copy-paste-bug-then-reintroduced-it-now-its-fixed-again/5307782 — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._