I am trying to go through the "Get Started with the Salesforce Platform" trail. In this trail we create the DreamHouse app to use throughout the trail  I have successfully installed the App.  The next step is to "Click the Data Import tab and click Initialize Sample Data".  I have tried this repeatedly over the last couple of days and it will not import.  When I click on "Initialize Sample Data" it just hangs until I shut it down - have let it go for 30 minutes and still just hangs.  No error message or anything else.
 

Any idea how to get this to initialize so I can get on with seeing this app and moving on in the trail?