Unable to create a Android build

I go to build my game for Android and get a slew of errors in the External Tools under Preferences. (Screen shot below)

It looks like Unity doesn’t actually install the files that are needed to do this. Does Unity have an additional install file that cares of this problem?

Let me clarify. I more than likely did not install the necessary files. I am sure I breezed right through that section of the install.

I don’t know if I am getting closer or further away here, but I followed this advice here:

And that clear up the errors in the first post above. Now I get these errors when I build:

I have no idea where to go from here.