finder icon

Hi everybody, I have noticed that the preview mp3 cover artwork icon is disappeared in finder: I just can see a blank standard icon with a note. I tried everything, deleting and putting back preview in get info, changing open with by default, and even reinstalling iTunes ; this last option...

I was wondering if someone can tell me how to fix this issue with my finder icon, it has a green color around it; possibly removing and re-adding it? I dont know what happened, my computer locked itself out and then it looked like that; I would appreciate some help!