So I\'m trying to make a simple textpath .svg that would be a vertical line with some text. The problem I am getting is that the tags seem to throw everything off. I think
Your sample will work fine inlined in a browser, because the browser knows about the xlink namespace.
If your SVG is an external file, then more strict XML parsing is performed and all namespaces used have to be defined.
All you need to do is add a definition for the xlink namespace to your outermost element.