Hi Kent,
As you mentioned you've tried to fix this issue using Open and Repair and other methods. I think you should also try these methods-
- Make sure that the file and the folder where the file is saved have the necessary permissions for all users. Make sure users have the necessary read and write permissions.
- Disable the Preview Pane feature in Windows Explorer as it can sometimes lead to such situations. If it is enabled, you simply click on "Preview Pane" again to disable it.
- Check the Anti Virus settings to ensure it is not causing conflicts or locking Excel files. Try disabling it temporarily.
- Make sure that both Windows and Office are up to date with recent updates.
Best Regards.