When trying to upload a schema into mendix 6.6 , I get this error: Type 'folderNodeType': This 'Choice' element is not supported in export mappings.

When trying to upload a schema into mendix 6.6 , I get this error: Type 'folderNodeType': This 'Choice' element is not supported in export mappings. The snippet of this type is below. What could be minimal edit needed in this xsd to make mendix accept this xsd?

<xs:complexType name="folderNodeType">
    <xs:complexContent>
        <xs:extension base="chatflowNode">
            <xs:sequence>
                <xs:choice maxOccurs="unbounded" minOccurs="0">
                    <xs:group ref="commonChatflowNodePropertiesChilds"/>
                </xs:choice>
                <xs:choice maxOccurs="unbounded" minOccurs="0">
                    <xs:group ref="commonChatflowNodeChilds"/>
                    <xs:element type="conceptNodeType" name="concept"/>
                </xs:choice>
                <xs:element name="autoLearnVariations" minOccurs="0">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="item" type="xs:string" minOccurs="0" maxOccurs="unbounded"/>
                        </xs:sequence>
                    </xs:complexType>
                </xs:element>
            </xs:sequence>
            <xs:attribute type="xs:string" name="label" use="optional"/>
            <xs:attribute type="selectionTypeType" name="selectionType" use="optional"/>
        </xs:extension>
    </xs:complexContent>
</xs:complexType>