The problem is , and I am going to describe it again:

When an XML comes with invalid characters like - é , o' (not necessary spanish characters) I get the following error when the xml is loaded.

Error Loading xml document: Invalid character in the given encoding.

And the way the program is loading the xml is

doc = New Xml.XPath.XPathDocument(New IO.MemoryStream(XMLContent))

How do i fix it?