Microsoft releases additional fix for major Windows 11 22H2 file copy kernel bug

Microsoft released the final Windows 11 Dev Channel build for Insiders yesterday. The new build, 25267, adds more Taskbar search bar style experiments and has a lot of bug fixes. Speaking of bug fixes, the latest build resolves one of the major issues on Windows 11 22H2 that was causing slowdowns when copying large files over networks. The issue was apparently affecting local files too. And although it was suspected to be related to the SMB initially, it was later found to be much more deep-rooted.

Ned Pyle, the Principal Program Manager in the Microsoft Windows Server High Availability and Storage group, has updated the blog post that described the issue. He writes:

An updated version of this preview fix is now available in Windows 11 Insider Preview Build 25267. This version "Fixed an issue where restartable copies of a file (for example using robocopy) with alternate data streams were hanging frequently in the latest Dev Channel builds."

Pyle mentions "updated" as Microsoft had already released an initial fix for the bug in a previous Windows build 25252. Of course, this is still in preview and Pyle says that the final fix will be released publicly later in a monthly update.

The final fix for Windows 11 22H2 production computer will come in a normal monthly Cumulative Update through Windows Update once validated in Insider builds.

You can find Ned Pyle's write-up here.

Microsoft releases additional fix for major Windows 11 22H2 file copy kernel bug