Hello,
May I know this problem occur when copying all types of files? If possible, you can restart the server and copy other files for testing.
For this question, first, verify the permissions of the 'Past Due' folder. Ensure that the user account or the service account that's copying the files has the appropriate permissions.
Besides, the file system might be corrupted. Run a disk check to scan for and fix file system errors. You can do this by using the chkdsk
utility in Command Prompt. And check if there's any third-party software or security software that could be interfering with the normal operation of the file system.
Additionally, please ensure that the server is fully updated with the latest Windows updates. You can also check the Event Viewer for any logs when the folder disappears.
I hope this helps.
Best regards