Playlist window is not themed

[blodsugare]

Can you please tell me what is going on here? I've been using SMplayer on Ubuntu 14.04 like for 2-3 years now an after I upgraded SMplayer to recent 16.6 version the playlist doesn't get themed at all anymore it doesn't matter what environment I apply the Main player window does get themed but the Playlist window does not.. it just stays white all the time and the popup window to open or add the new files to the playlist looks like Win98 style kinda.

[blodsugare]

I was trying to solve it for some time but luckily the issue was solved after I posted it dunno why or how did it happen but when I jumped to SMplayer configuration settings: Options --> Preferences --> Interface the "style" setting was set to "default" and I manually changed it to GTK+ and everything went back to its previous state.