In the XSL I am using the document(uri)
function to retrieve documents, this function works if the uri is in this
folder, but since I need it to take a http uri, it throws me back this error

file:///C:/Projects/doctest.xsl; Line #6; Column #-1; C
an not load requested doc: Expected "</META>" to terminate element starting
on l
ine 3.

The problem is in the document zou attempt to lead with
document(). I suspect the server found  a problem and
serves an error document rather than the XML document
you expect.