Upon opening an embedded image in a pdf from okular I was with presented with a gwenview error message reading: "There are two actions (Cut, Delete) that want to use the same shortcut (Shift+Del). This is most probably a bug." I apologize if I have misclassified any elements within this report. Also, if this is not the appropriate method for reporting the issue please let me know.
@stephen I have a similar issue and found more info' here: https://bugs.kde.org/show_bug.cgi?id=377880
*** This bug has been marked as a duplicate of bug 377880 ***