title: Invalid particle derivation by restriction for schema
body: <p>How can I remove the below warning in the xsd. mymain.xsd refers to mysecond.xsd</p>
  
  <p>my main.xsd</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;&lt;xsd:schema elementFormDefault="qualified" targetNamespace="http://abc.com" version="2.0" xmlns:tyu="http://abc.com" xmlns:my="def.com"  xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt;
    &lt;xsd:import namespace="def.com" schemaLocation="mysecond.xsd"/&gt;
    &lt;xsd:complexType name="myType"&gt;
      &lt;xsd:complexContent&gt;
       &lt;xsd:restriction base="my:myType"&gt;
        &lt;xsd:sequence&gt;
          &lt;xsd:element minOccurs="0" name="rty" type="tyu:myagainType"/&gt;
        &lt;/xsd:sequence&gt;
      &lt;/xsd:restriction&gt;
     &lt;/xsd:complexContent&gt;
    &lt;/xsd:complexType&gt;
    &lt;xsd:complexType name="myagainType"&gt;
      &lt;xsd:complexContent&gt;
       &lt;xsd:restriction base="my:myagainType"&gt;
        &lt;xsd:sequence&gt;
          &lt;xsd:element minOccurs="1" name="uid"&gt;
          &lt;xsd:simpleType&gt;
             &lt;xsd:restriction base="xsd:string"&gt;
            &lt;xsd:maxLength value="1"/&gt;
             &lt;/xsd:restriction&gt;
          &lt;/xsd:simpleType&gt;
          &lt;/xsd:element&gt;
        &lt;/xsd:sequence&gt;
      &lt;/xsd:restriction&gt;
     &lt;/xsd:complexContent&gt;
    &lt;/xsd:complexType&gt;  
  &lt;/xsd:schema&gt;
  </code></pre>
  
  <p>mysecond.xsd</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;&lt;xsd:schema elementFormDefault="qualified" targetNamespace="def.com" version="2.0" xmlns:my="def.com" xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt;
    &lt;xsd:complexType name="myagainType"&gt;
      &lt;xsd:sequence&gt;
        &lt;xsd:element minOccurs="0" name="klo" type="xsd:string"/&gt;
      &lt;/xsd:sequence&gt;
    &lt;/xsd:complexType&gt;
    &lt;xsd:complexType name="myType"&gt;
      &lt;xsd:sequence&gt;
        &lt;xsd:element minOccurs="0" name="rty" type="my:myagainType"/&gt;
      &lt;/xsd:sequence&gt;
    &lt;/xsd:complexType&gt;
  &lt;/xsd:schema&gt;
  </code></pre>
  
  <p>warning</p>
  
  <pre><code>Warning 1   Invalid particle derivation by restriction - 'Derived element 'http://abc.com:rty' is not a valid restriction of base element 'def.com:rty' according to Elt:Elt -- NameAndTypeOK.'.    D:\files\mymain.xsd 3   4
  </code></pre>