XML invalid child element same as expected

I have created some xsd schemas and receive the below error when trying to read from it in c#

The element 'PartnerPSTNTransfer' in namespace 'http://localhost/Orders-PartnerPSTNTransfer-v1-0' has invalid child element 'StartDate' in namespace 'http://localhost/Orders-Connection-v1-0'. List of possible elements expected: 'StartDate' in namespace 'http://localhost/Orders-PartnerPSTNTransfer-v1-0'.

However the expected element is StartDate and it is present in the xml file so I am unsure why this error would be shown. I'll attatch the .xsd for the schemas i created:

<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="PartnerPSTN"
    targetNamespace="http://localhost/Orders-PartnerPSTN-v1.0"
    elementFormDefault="qualified"
    xmlns="http://localhost/Orders-PartnerPSTN-v1.0"
    xmlns:mstns="http://localhost/Orders-PartnerPSTN-v1.0"
    xmlns:xs="http://ift.tt/tphNwY"
    xmlns:a="http://localhost/Orders-Address-v1-0"
    xmlns:c="http://localhost/Orders-Common-v1-0" >

  <xs:simpleType name="Contract">
    <xs:restriction base="xs:token">
      <xs:enumeration value="Monthly_12"></xs:enumeration>
    </xs:restriction>
  </xs:simpleType>

  <xs:simpleType name="PackageOption">
    <xs:restriction base="xs:string">
      <xs:enumeration value="Data Only" />
      <xs:enumeration value="Free Evening and Weekend" />
      <xs:enumeration value="1000 Anytime" />
    </xs:restriction>
  </xs:simpleType>

  <xs:simpleType name="FeatureOption">
    <xs:list>
      <xs:simpleType>
        <xs:restriction base="xs:string">
          <xs:enumeration value="Feature0"/>
          <xs:enumeration value="Feature0.A"/>
          <xs:enumeration value="Feature0.B"/>
          <xs:enumeration value="Feature0.C"/>
          <xs:enumeration value="Feature1"/>
          <xs:enumeration value="Feature2"/>
          <xs:enumeration value="Feature2.A"/>
          <xs:enumeration value="Feature3"/>
          <xs:enumeration value="Feature3.A"/>
          <xs:enumeration value="Feature3.B"/>
          <xs:enumeration value="Feature3.C"/>
        </xs:restriction>
      </xs:simpleType>
    </xs:list>
  </xs:simpleType>

  <xs:complexType name="PartnerPSTNConfiguration">
    <xs:sequence>
      <xs:element name="Package" type="PackageOption" />
      <xs:element name="Feature" type="FeatureOption" />
    </xs:sequence>
  </xs:complexType>
</xs:schema>

Schema 2:

<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="PartnerPSTNTransfer"
    targetNamespace="http://localhost/Orders-PartnerPSTNTransfer-v1-0"
    elementFormDefault="qualified"
    xmlns="http://localhost/Orders-PartnerPSTNTransfer-v1-0"
    xmlns:mstns="http://localhost/Orders-PartnerPSTNTransfer-v1-0"
    xmlns:xs="http://ift.tt/tphNwY"
    xmlns:a="http://localhost/Orders-Address-v1-0"
    xmlns:padsl="http://localhost/Orders-PartnerPSTN-v1.0"
    xmlns:c="http://localhost/Orders-Common-v1-0"
    xmlns:conn="http://localhost/Orders-Connection-v1-0">

  <xs:import namespace="http://localhost/Orders-Common-v1-0" schemaLocation="../../Common.xsd" />
  <xs:import namespace="http://localhost/Orders-PartnerPSTN-v1.0" schemaLocation="PartnerPSTN.xsd" />

  <xs:complexType name="PartnerPSTNTransfer">
    <xs:sequence>
      <xs:element name="TelephoneNumber" type="c:Landline" />
      <xs:element name="StartDate" type="xs:date" />
      <xs:element name="Postcode" type="c:RequiredString" />
      <xs:element name="Configuration" type="padsl:PartnerPSTNConfiguration" />
    </xs:sequence>
  </xs:complexType>

  <xs:element name="PartnerPSTNTransfer" type="PartnerPSTNTransfer"></xs:element>
</xs:schema>