Hi James
I solved by deleting this section 'http://schemas.microsoft.com/office/infopath/2007/PartnerControls:Person' from xsd header, then i merge the content of BuiltInActiveXControls.xsd in this section below into myschema.xsd :
<xsd:element name="Person">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="my:DisplayName" minOccurs="0"/>
<xsd:element ref="my:AccountId" minOccurs="0"/>
<xsd:element ref="my:AccountType" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="DisplayName" type="xsd:string"/>
<xsd:element name="AccountId" type="xsd:string"/>
<xsd:element name="AccountType" type="xsd:string"/>
But change tag "<xs>" into "<xsd>" and also change tag "pc:" into "my:", like above.
Then I put above code below the section :
<xsd:element name="group_1">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="my:Person" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
So it will becoming like this :
<xsd:element name="group_1">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="my:Person" minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="Person">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="my:DisplayName" minOccurs="0"/>
<xsd:element ref="my:AccountId" minOccurs="0"/>
<xsd:element ref="my:AccountType" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="DisplayName" type="xsd:string"/>
<xsd:element name="AccountId" type="xsd:string"/>
<xsd:element name="AccountType" type="xsd:string"/>
then run xsd myschema.xsd /c. It works for me.
Thanks