I copied my work from my school computer to my home computer. Because of that my drawing files don't know where to find the part files. I used to get a pop up window that asks me to browse for the part file, but I clicked the don't show this again option. I don't know where to find that again.
Eric,
In the tree on your drawing RMB and choose show.
Since it asked me if I was sure I wanted to save I am assuming I am on a future version of software. Your views are hidden for some reason.