Using shared SSL to secure connections

I switched on Shared SSL because I want to use secure connections.
When I try to access a web page with https://…
I always get the error:
Server Application Unavailable
The web application you are attempting to access on this web server is currently unavailable. Please hit the “Refresh” button in your web browser to retry your request.
Administrator Note: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur.

What am I doing wrong?

TIA,
Miguel Pena

As per your ticket you were using the incorrect URL.
Kindly use the correct one as mentioned in my reply.