I wanted to give you a head's up that the course NT313 keeps crashing when I hit continue. This happens every time when I am trying to get past a recommended resource that is locked & not in my library. I am running this on a MacBook Pro, with the latest masOS High Sierra (10.13.2) which was just updated today.
Occasionally when I try to view the recommended source, just to see how much the resource costs, I can do this, but not always. It seems to crash immediately, without allowing me to get past the recommended resource, especially when I hit continue. This has happened 4 times already.