Just to add to this article, sandbox.hortonworks.com needs to be mapped to the ip address of the sandbox virtual machine. Typically out of the box, the VirtualBox version uses the loop back ip 127.0.0.1 vs. the Vmware image provides an IP generated dependent on the network vm settings configured. Thus, if you don't have sandbox.hortonworks.com in your hosts file on your machine, use the ip address instead such as http://127.0.0.1:4200
