XML : XML table not showing after including XSD

I have a XML table written, and have made a XSD to validate it with. Now according to this validator (validome, as always not working) the schema valiates fine and everything is correct. The problem is the fact that when I implement the xds to the xml...the table simply dissapears.

Here is how the xml is implemented + example of table element (polish)

  <?xml version="1.0" encoding="UTF-8"?>  <!-- DTD <!DOCTYPE gry SYSTEM "valid.dtd">  -->      <?xml-stylesheet type="text/xsl" href="gry.xsl"?>  <gry xmlns="http://www.w3schools.com/RedsDevils"            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"            xsi:schemaLocation="http://www.w3schools.com/RedsDevils schema.xsd">    <gatunek id="FPS">      <gra nazwa="Star Wars: Battlefront" PC="y" XBOXONE="n" PS4="n">        <producent> DICE </producent>        <wydawca> Electronic Arts </wydawca>        <cena> 120 </cena>        <data_wydania>2015-10-10</data_wydania>        <metacritic>86</metacritic>        <cover>img/swb.jpg</cover>              <opis>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</opis>      </gra> </gatunek> </gry>    

And how the xsd starts:

  <?xml version="1.0" encoding="UTF-8"?>  <xs:schema targetNamespace="http://www.w3schools.com/RedsDevils"      elementFormDefault="qualified"      xmlns="http://www.w3schools.com/RedsDevils schema.xsd"      xmlns:xs="http://www.w3.org/2001/XMLSchema">      <xs:element name="gry" >  <xs:complexType> (...)    

When I remove the xsd definition from the xml the tables show up fine.

What could be the reason behind this problem, and how can I fix it?