Importing zombie toy assets not fully working on Unity 5.5

So I am trying to follow the unity certification courceware since I got it for free with my upgrade and when I try to import the zombie toys 1-3 assets, a bunch of the assets that I can't import. a bunch of the assets are unchecked by default and trying to check them does nothing, even clicking the all button just does nothing. How can I resolve this problem as it is going to be pretty hard to follow the courseware without the assets?