Upfront-Fixer theme just keeps "loading"

I am trying to add modify the Upfront-Fixer theme for the first time, but it just keeps "loading". It is 'thinkin'/moving, but will not progress beyond loading...now at about 5 minutes. I loaded and activated it, but I must have missed something.
I also used the Theme Tester, but I now deactivated that, just in case.
Now my old theme won't work either...no menu, etc.