Microsoft warns system administrators that a file copy, save, and attach issue is affecting apps in Windows 11 and 10. Fortunately, File Explorer is not affected.
Microsoft also says that 32-bit applications that use the CopyFile API are affected. This API essentially helps to copy a new file to an existing file and track the progress. So with this feature currently broken, copying and saving has become a very big problem for affected apps.
Microsoft also added that 32-bit versions of Office applications, such as Word and Excel, are also affected, and that users may see a “The document was not saved” error. Microsoft explains the issue in detail on the Windows support page.
There is one positive though. Microsoft says the problem is intermittent, meaning that repeating the same action could likely resolve it.
The company mentions as a possible solution:
Solution: To alleviate the problem, you can try to save or copy the file again. Since the issue is intermittent, it is likely to succeed on a subsequent try.
However, the above solution is only for Windows 11 22H2. For other versions of Windows 11 and Windows 10, Microsoft recommends doing a known issue rollback (KIR from known issue rollback):
Solution: To alleviate the problem, you can try to save or copy the file again. Since the issue is intermittent, it is likely to succeed on a subsequent try. Important: If the solution below does not resolve intermittent save or copy issues in your environment, then you may be experiencing a different issue with similar symptoms.
Resolution: This issue is resolved using the Known Issue Rollback (KIR). Enterprise-managed devices that have installed an affecting update and have this issue can resolve this by installing and configuring a special Group Policy.
The special Group Policy is located at
Computer Configuration > Administrative Templates.
Group Policy downloads with Group Policy name:
Download for Windows 11, version 21H2 - KB5023774 230222_032017 Known Issue Rollback
Download for Windows 10, version 22H2; Windows 10, version 21H2 - KB5023773 230222_032013 Known Issue Rollback
Important: You will need to install and configure Group Policy for your version of Windows to resolve this issue.
To mention that Microsoft recently solved an SMB file copy problem in Windows 11 21H2 with the update preview KB5026436.