Got my own crash from pattern of actions described by Devil on the second try.
Now I'm thinking if I should upload crash dump via Kolor Crash Reporter which popped up. Web addresses mentioned in message are autopano.net and http://www.kolor.com
, none of them are xnview.com, so I don't know how they are related.
Something funny was happening when I started XnView MP on a first try before it showed me picture after I have closed Configuration Wizard. File XnView.db-journal was appearing and disappearing and appearing and disappearing (and so on multiple times) in folder, but maybe it is just by design.
Main message is that yes, you can crash XnView MP 0.79 that way.
And after more testing yes, bug with renaming of 3rd file instead of 2nd works too.