deleted pictures - Deleting Duplicates

[bert maetens]

Over the years I had a tremendous amount of doubles (2 times the same pictures) in my libary. I used an external software to delete all the doubles.

With LR6 there was a question mark next to the deleted picture.   It was easy to delete those within LR

With the LR 3.1 cloud version I do not see any question mark anymore next to the picture that I deleted with the external software.... and all the deleted pictures are still visible...

How can I correct this now?

{Title edited by Moderator for clarity and to aid search queries} 

[JohanElzenga]

What software did you use and how did you delete those images? I don't think you can delete Lightroom (cloud) duplicates with external software, because the images are in the cloud.