I have installed he generator, set all the permissions, etc.  I can see the home page and save the configuration.
When I click on Crawling tab I get this:
Please wait. Sitemap generation in progress...
Internet Explorer cannot display the webpage 
   
Most likely causes:
You are not connected to the Internet. 
The website is encountering problems. 
There might be a typing error in the address. 
I had paid for the installation service, but decided to give it a go on my own.  It seemed easy to install and I don't understand why I am having issues with it.  I have already re-installed it about 3 times trying to get it to work.