Microsoft has reported that some 32-bit applications experience recurring issues when copying and saving files across different versions of Windows, particularly when copying to network shares. The problem only occurs in apps that are “large address aware” and use the CopyFile API on Windows 11 21H2 and 22H2 after installing KB5023774 and later updates, or Windows 10 21H2 and 22H2 after installing KB5023773 and later updates.
In a statement, Microsoft said that Windows devices are more likely to be affected by this issue when they run some commercial/enterprise security software that uses extended file attributes. Redmond claims that it has not yet received any reports that File Explorer’s copy function has been compromised, but the CopyFile API may not remain intact.
Microsoft Office apps such as Excel and Word may be susceptible to this issue when using 32-bit versions, resulting in a “Document not saved” error. However, this issue may not affect consumers using Windows in personal or non-managed commercial settings. Microsoft has not yet addressed the issues in the latest release, Windows 11 version 22H2.
Microsoft suggests affected customers can work around the problem by re-saving or copying the files until the fix is complete. In Windows 10 and 11 21H2, the issue has been resolved by using the Known Issue Rollback, which can roll back bugs pushed through a Windows Update. To deploy the Known Issue Rollback, admins need to install a KIR Group Policy, which can be found under Computer Configuration -> Administrative Templates. The Group Policy can be obtained from Microsoft (.msi files) from the links provided on the Microsoft support site.