Hello,
The URL with which to register the Big Data Extensions plug-in should be unchanged. Aside from receiving a 404 error, are there any other error messages?
One possible problem could be if your browser is using a proxy, and you're using the IP address of the server. If you want to use the server IP address to access the vSphere Web Client and your browser uses a proxy, add the server IP address to the list of proxy exceptions.
I hope that helps. Please let us know if you continue to have issues.
Kind Regards,
Chris Bedford