Reply to sample triggering

Hi guys!
I'm trying to map up my sample decks, simply having 8 play buttons in a row.

I used the same technique as Ean in the latest video about cue point juggling, using the "sample trigger" command. But when I press my buttons, I get the error "deck needs a track to copy to sample slot". Don't really understand this message, since I have loaded up stuff in all the sample (and regular) decks.

How have you mapped up your sample decks, and do you have any thoughts?