non-DiskXtender file(s)

I have set up a purge rule to purge any file in the folder, but no files have been purged.

I tried to manually purge the files/folders from the Windows Explorer context menu, but I get and error.

The error reads:

DxShell

0 file(s) were successfully purged.

10 file(s) were skipped because they are non-DiskXtender file(s).

How do I designate these files as DiskXtender files for purging?