Hi, <br><span class="gmail_quote"></span><br><div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hmm, I think the &quot;NULL&quot; comes from the fact that you only use &quot;SYSTEM&quot;,<br>
 without providing an ID. libxml2 printf()&#39;s the ID here.<br> <br> So, well, it can&#39;t find it on your system. Have you tried something like<br> <br> &quot;file://C:/Desarrollo/pythontests/lxml/foo.dtd&quot;<br> <br>
 ?<br> <br> And: have you made sure the file is actually there?</blockquote><div><br>All the files are in the right place, so that is not the problem. <br>I tried &quot;file://C:/Desarrollo/pythontests/lxml/foo.dtd&quot;, bang, same failure.<br>
But &quot;C:/Desarrollo/pythontests/lxml/foo.dtd&quot; does work!. <br>&quot;foo.dtd&quot; works too (foo.xml is in the same location).<br><br>I&#39;m wondering why, in the unsuccessful cases, the resolver receives both url and id set to None, perhaps the parser doesn&#39;t like backward slashes.<br>
Any idea?<br>&nbsp;</div><br></div><br>