If I delete a picture (Shift+Del) which is inside a group (I usually group duplicated pictures), that picture still appears in the thumbnail view as part of that group, which you can show and hide. Double clicking the image just gives you a blank preview windows, and deleting it again shows a message saying "File/folder <path to file.jpg> does not exist". Re-reading the metadata or updating the thumbnails does not seem to remove the non-existent picture from the thumbnail view. Ungrouping the picture previous to its deletion seems to work, though.
Git commit 248b829b3eda8cc8993503fa69059e1730a340e4 by Maik Qualmann. Committed on 04/04/2018 at 21:16. Pushed by mqualmann into branch 'master'. remove deleted items from the group FIXED-IN: 6.0.0 M +2 -1 NEWS M +4 -1 core/app/items/imageviewutilities.cpp M +1 -0 core/libs/iojobs/iojob.cpp https://commits.kde.org/digikam/248b829b3eda8cc8993503fa69059e1730a340e4