• in hibernate facet configuration dialog add new configuration file. File is created on disk and is present in Descriptors page of settings.
• close dialog. Select the file in project tree and delete it
• open the project settings again:
  the configuration file is still present on the descriptors tab. You can edit this entry with no results.
  The entry that references no file should be at least red-highlighted

Related issue, i believe:
if i edit the entry in descriptors tab and manually type the unexisting file name there, i get the similar confusing results - the entry that references no files. The file is not created, i get no signs that no such files exist