My son changed the TorusGeometry last parameter to a number with many zeroes 
The editor now crashes everytime it loads and cannot get to the part where I can reverse the change.
Any way to load the page without rendering?
My son did the same thing when he was testing the book! Great minds think alike, eh? 
Check out the section named “Recovering When 3DE Is Broken” in chapter 2. That covers just this situation 
If you’re still having problems after following those steps, let me know!
-Chris