I figured out how to make it work on my MacBook Pro. I couldn't get past the start page. So I logged in to wgt.com on another laptop (with windows) and it came up with the START button on the left, like normal. I clicked on START and it took me to the menu page with the golf course in the background. I wrote down the web address for this page:
I typed that into my Safari browser and it took me to the same menu with the golf course in the background, as a guest. There is a LOGIN in the middle of the page. After logging in, everything is normal and you can play wgt again.