I know several people have reported this problem before, where some pictures can't be deleted (you . I was unable to find any posts where a solution was offered that worked for me. However, I found a solution that worked for me, so I thought I would post here in case it also works for someone else.
I discovered that these same pictures were being locked (protected) on my camera, but I hadn't noticed since I reformat my memory card rather than deleting the pictures on it. This protected status would transfer over when I would upload the pictures to my computer, and those are the ones that I couldn't delete.
I couldn't find a way within XnViewMP to remove the protected flag, but I was able to do so with ViewNX 2, after which the pictures can be deleted in XnViewMP, as well.
Unable to delete some pictures
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