This is my first night using wpmudev, so I very well may

This is my first night using wpmudev, so I very well may be overlooking something. I did a few searches and read some docs, but I cant figure out what's going on. When I click on the Customize or Upfront button at the top, it goes to the loading screen and just sits there spinning. I've let it sit there loading for 5 minutes or so with no change.

Can anyone help?

I have wordpress 4.3.1 installed
I've installed the fixer theme and a few widgets
os x 10.11
firefox 41.0.1