I maintain that old inherited software that uses basically zip files with a custom file extension to load and save “learning situations” – usually two sqlite databases and sometimes an image file.
The old software used a zip module I think written or adapted by Thomas Tempelmann, and this was slowly falling apart due to folder item and system changes. So I replaced that with Einhugur ZipArchive. What looked like an easy modernization has now revealed a lot of issues on Windows. When overwriting a save, I was renaming the folder item of the old zip file until the new one was written, deleted the first and renamed the second. All no problems.
Under Windows, the errors were hidden. Renaming did not work but caused neither error nor exception, and when I try different approaches best result so far is Windows showing a notification that the file cannot be overwritten as it is still opened by my app. Which is not true. The real working files are different from this zip and in a different location; only reference I hold is the temporary folderitem I need to handle it.
Any ideas what could make Windows believe the folder item is opened with error 104? It has write access, it’s not locked.