The first thing you should try is simply to use a browser that is not Google Chrome.
By default, Chrome uses the HTTPS protocol when a user navigates to a websites by manually typing a URL. You are probably not going to be able to connect to the HDP Sandbox welcome page using the HTTPS protocol, because in order to do so, you would need to enable HTTPS on the web server embedded with the HDP Sandbox installation. As it is delivered via the Cloudera website, the HDP Sandbox is not set up for this (although a sophisticated UNIX/Linux system administrator could get it to work with sufficient effort). That is why, when the browser attempts to use HTTPS, you get an error message in response that indicates the server "can't provide a secure connection".
By using a different browser which does not use this default behavior, you should be able to access the HDP Sandbox Welcome page using the HTTP protocol.
The second thing you should try is to type out the full URL in the browser location bar.
You can do this by not relying on the browser to supply the protocol and manually specify HTTP by intentionally typing, for example, http://localhost:4200/ (beginning with the http://) in the browser location bar. Indeed, if you closely examine the screen shots in the Sandbox Deployment and Install Guide, you'll see that nowhere do they indicate that you should use the https:// protocol prefix to initiate your Hortonworks Sandbox session. It's easy to get confused on this point because the URLs for the documentation and the HDP Sandbox download website do specify the https:// protocol prefix.
... View more