Custom pipeline (XML validator) error

I have created my custom pipeline because I want my incoming XML to be validated. When I validate my xml test instance against the schema in visual studio, I get no errors.

But I get this error when I use my custom pipeline to validate my xml:

The published message could not be routed because no subscribers were found. This error occurs if the subscribing orchestration or send port has not been enlisted, or if some of the message properties necessary for subscription evaluation have not been promoted. Please use the Biztalk Administration console to troubleshoot this failure.

Also when I look at the message, the message type is blank?

This is an example of my schema:

?xml version="1.0" encoding="utf-16"?>
<xs:schema xmlns:ns0="…" targetNamespace="…" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="Root">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="field1" type="xs:string" />
        <xs:element name="field2" type="xs:string" />
        <xs:element name="field3">
          <xs:complexType>
            <xs:sequence>
              <xs:any minOccurs="0" maxOccurs="unbounded" processContents="skip" />
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

Could this problem comes from the use of an <any> element? I have set the processContents to skip to avoid this node to be validated.

Did someone have an idea of what I am doing wrong?

Thanks.