Face Annotations that have "lost their Face Data"

[Tveloso]

On a couple of recent occasions (once in an earlier version of IMatch, and once in the latest version - 2020.5.6), I noticed that "normal" (non-manual) Face Annotations, that I had previously confirmed, were now appearing with the diagonal line through the face box...and they either had the question mark (i.e. the previously assigned person was no longer assigned):

     ................
     :'.            :
     :  '.          :
     :    '.        :
     :      '.      :
     :        '.    :
     :          '.  :
     :............'.:
            ?

...or still had the originally assigned Persion's Name:

     ................
     :'.            :
     :  '.          :
     :    '.        :
     :      '.      :
     :        '.    :
     :          '.  :
     :............'.:
       Person Name

...both on a dark (not green) background...(this indicates that the Annotation has no Face Data, correct?)

I suspect that the latter state (where the Face Annotation has no Face Data, but still has a Person assigned) is the most unusual, as it represents a type of Annotation that we cannot create ourselves, via the functionality in IMatch.

I have a sense that the condition might actually have been created in earlier versions of IMatch 2020, and may no longer be able to be created, but I'm not sure of that.  The first time I encountered the condition, I just re-assigned the correct persons to the Annotations, and decided not to report it, as a number of bug fixes were pending to be released.  But when I encountered it again a few days ago, I saved (i.e. didn't correct) one of the files, so I could report it.

It then occurred to me that I might be able to search for all instances of that condition, and I found 5 other files that had it.  From the Collections View, I selected the People Node:

       

...and then used the People Filter to look for Files without Faces:

       

This turned up 6 files:

       

...which I noticed were all part of Manual Stacks (none was the Stack Top).  Perhaps Stacking has something to do with the creation of this condition?... 

Another thing I noticed is that when I opened the Stacks Panel, and viewed some of the other files in each stack, there were other files that also had the condition (but were not appearing in my filtered FileWindow).

I'll keep an eye out for other instances of this condition, in case its actually still an issue...and will keep the "bad files" in that state in case there's anything that Mario would like to inspect about them.

[Mario]

Regular Stacking: No.
Do you use versioning?

[Tveloso]

I intend to learn about, and set up Versioning, but I haven't done so yet.

The Stacks were created manually in the File Window via Shift-S.