I have the following XML `complexType`s defined:

```
<xs:complexType name="loss">
    <xs:all>
        <xs:element name="lossCause" type="xs:string"/>
        <xs:element name="lossDate" type="xs:dateTime"/>
        <xs:element name="lossDescription" type="xs:string"/>
        <xs:element name="lossLocation" type="address" minOccurs="0"/>
        <xs:element name="lossTime" type="xs:string" minOccurs="0"/>
        <xs:element name="officials" minOccurs="0">
            <xs:complexType>
                <xs:sequence>
                    <xs:element name="official" type="official" minOccurs="0" maxOccurs="unbounded"/>
                </xs:sequence>
            </xs:complexType>
        </xs:element>
    </xs:all>
    <xs:attribute name="incidentOnly" type="xs:boolean" use="required"/>
    <xs:attribute name="lawsuit" type="xs:boolean" use="required"/>
</xs:complexType>

```

and:

```
<xs:complexType name="propLoss">
    <xs:complexContent>
        <xs:extension base="loss">
            <xs:all>
                <xs:element name="damageDescription" type="xs:string"/>
                <xs:element name="property" type="property"/>
                <xs:element name="responsibleParty" type="contact" minOccurs="0"/>
            </xs:all>
            <xs:attribute name="businessOperational" type="xs:boolean" use="required"/>
            <xs:attribute name="propertyLivable" type="xs:boolean" use="required"/>
            <xs:attribute name="weatherRelated" type="xs:boolean" use="required"/>
        </xs:extension>
    </xs:complexContent>
</xs:complexType>

```

However, upon validation, I get an error stating that the `all` model group isn't allowed within the `loss` `complexType` nor its extension `propLoss` definition. What is it that I'm doing wrong?

Thanks!