Error 500

Hi there, I am new to web design and have recently tried to upload a page. I am
receiving an error message 500 which I understand is due to "Couldn't retrieve
the HTML document because of server-configuration problems. Contact site
administrator" Any idea what I am doing wrong

A error 500 is a server error. In other words the server was not able to load
the page due to a server-side script error.

I'd check your code or permissions, one of the two must be causing the problem.