This question just started popping up recently :"There are unsaved changes, do you want to save the playlist". Could you tell how to turn it off? Thanks
I think there's no option to avoid that message but you can turn off the option "add files to the playlist automatically" to prevent smplayer to modify the playlist.
I got rid of this by unchecking the box "save playlist after leaving" , but mine is not in English so it may not exactly be named that way... to reach this box is : settings playlist various the 3rd box