Hm..
If it is plain HTML you should not get any error messages, as HTML is not interpreted as a programming language. It would just not show things the way expected.
Have you set your server to interpret all HTML files as PhP or something like that?
That being said, this looks odd to me:
<meta http-equiv="refresh" content="0;url= Site/Welcome.html" />
Don't you need some quotes? (Although I do not use refreshes)
<meta http-equiv="refresh" content="0"; url= "Site/Welcome.html" />