Fallout new vegas dennis crocker?

I have been approached by the NCR and he gives me the note saying that Crocker needs my help. I forgot, and now i'm basically done with the game. I worked with Yes Man, if it matters. I'm liked by NCR. I go into the emby, and Crockers nowhere to be found! I have another file of it, of which he does appear, so i know where he is, he just not there! HELP!