Hi I'm having some issue trying to generate a class from WSDL document.
I'm getting Error: Failed to parse wsdl: Unable to find schema for element; {http://www.w3.org/2001/XMLSchema}schema

Here is part of my WSDL document. 

<wsdl:definitions xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:s="http://www.w3.org/2001/XMLSchema" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:tns="http://tempuri.org/StandardCallAPI/SCAPI" xmlns:tm="http://microsoft.com/wsdl/mime/textMatching/" xmlns:mime="http://schemas.xmlsoap.org/wsdl/mime/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://tempuri.org/StandardCallAPI/SCAPI">
<wsdl:types>
<s:schema elementFormDefault="qualified" targetNamespace="http://tempuri.org/StandardCallAPI/SCAPI">
<s:import namespace="http://www.w3.org/2001/XMLSchema"/>
<s:element name="CreateUser">
<s:complexType>
<s:sequence>
<s:element minOccurs="0" maxOccurs="1" name="LoginUsername" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="LoginPassword" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="UserExternalID" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="AdvertiserExternalID" type="tns:ArrayOfString"/>
<s:element minOccurs="0" maxOccurs="1" name="NewUsername" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="NewPassword" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="NewName" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="NewEmail" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="phone" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="fax" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="ExpirationDate" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:complexType name="ArrayOfString">
<s:sequence>
<s:element minOccurs="0" maxOccurs="unbounded" name="string" nillable="true" type="s:string"/>
</s:sequence>
</s:complexType>
<s:element name="CreateUserResponse">
<s:complexType>
<s:sequence>
<s:element minOccurs="1" maxOccurs="1" name="CreateUserResult" type="s:boolean"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="UpdateUser">
<s:complexType>
<s:sequence>
<s:element minOccurs="0" maxOccurs="1" name="LoginUsername" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="LoginPassword" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="UserExternalID" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="AdvertiserExternalID" type="tns:ArrayOfString"/>
<s:element minOccurs="0" maxOccurs="1" name="NewUsername" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="NewPassword" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="NewName" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="NewEmail" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="phone" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="fax" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="ExpirationDate" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="UpdateUserResponse">
<s:complexType>
<s:sequence>
<s:element minOccurs="1" maxOccurs="1" name="UpdateUserResult" type="s:boolean"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="DeleteUser">
<s:complexType>
<s:sequence>
<s:element minOccurs="0" maxOccurs="1" name="LoginUsername" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="LoginPassword" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="UserExternalID" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="DeleteUserResponse">
<s:complexType>
<s:sequence>
<s:element minOccurs="1" maxOccurs="1" name="DeleteUserResult" type="s:boolean"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="RetrievePermissionByUser">
<s:complexType>
<s:sequence>
<s:element minOccurs="0" maxOccurs="1" name="LoginUsername" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="LoginPassword" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="UserExternalID" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="AdvertiserExternalIDs" type="tns:ArrayOfString"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="RetrievePermissionByUserResponse">
<s:complexType>
<s:sequence>
<s:element minOccurs="1" maxOccurs="1" name="RetrievePermissionByUserResult" type="s:boolean"/>
<s:element minOccurs="0" maxOccurs="1" name="AdvertiserExternalIDs" type="tns:ArrayOfString"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="RetrieveUserByPermission">
<s:complexType>
<s:sequence>
<s:element minOccurs="0" maxOccurs="1" name="LoginUsername" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="LoginPassword" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="AdvertiserExternalID" type="s:string"/>
<s:element minOccurs="0" maxOccurs="1" name="UserExternalIDs" type="tns:ArrayOfString"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<s:element name="RetrieveUserByPermissionResponse">
<s:complexType>
<s:sequence>
<s:element minOccurs="1" maxOccurs="1" name="RetrieveUserByPermissionResult" type="s:boolean"/>
<s:element minOccurs="0" maxOccurs="1" name="UserExternalIDs" type="tns:ArrayOfString"/>
<s:element minOccurs="0" maxOccurs="1" name="ErrorMessage" type="s:string"/>
</s:sequence>
</s:complexType>
</s:element>
<wsdl:service name="APIWebService">
<wsdl:port name="APIWebServiceSoap" binding="tns:APIWebServiceSoap">
<soap:address location="http://api.standardcall.com/scportal.asmx"/>
</wsdl:port>
</wsdl:service>
</wsdl:definitions>

Thanks.