Something is wrong.
What's the exact error message?
What URL are you trying to open?
Can you connect by bypassing the webadapter and going through the port?
More info on your setup will help. Is there a federated server, a data store, on different servers or the same one? etc...
Is this an HTTPS only setup?
When you connect locally (from RDC'd onto the server), is it going to local host or?
i.e. what's the URL that is connecting locally.
Depending on various things, it might be as simple as needing https at the front of your URL.