XML : XML Schema The element type "xs:element" must be terminated by the matching end-tag "‹/xs:element>"

When I validate my file it tells me this:

Well Formed
LOC 37, 3 The element type "xs:element" must be terminated by the matching end-tag "‹/xs:element>".

Here's my code:

      <xs:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">      <xs:annotation>       <xs:documentation xml:lang="pl">          XML Schema do pliku hobby.       </xs:documentation>    </xs:annotation>    <xs:element name="Hobby" type="Hobby_typ">  <xs:complexType name="Hobby_typ">     <xs:sequence>     <xs:element name="Muzyka" type="Muzyka_typ"/>   </xs:sequence>  </xs:complexType>    <xs:element name="Muzyka" type="Muzyka_typ"/>    <xs:complexType name="Muzyka_typ">    <xs:sequence>        ...  </xs:sequence>  </xs:complexType>    <xs:complexType name="utwory_typ">    <xs:sequence>      <xs:element name ="utwor" type="xsd:string" maxOccurs="unbounded"/>    </xs:sequence>  </xs:complexType>    </xs:schema>