Occasional error in MTD_MSIL2A.xml in Sen2Cor output

With some input datasets, I get an XML tag (GRI_List) appearing in MTD_MSIL2A.xml that is not in the schema, and this reports an error

In In MTD_MSIL2A.xml, line 491

 <GIPP_FILENAME type="GIP_VIEDIR" version="0005">S2A_OPER_GIP_VIEDIR_MPC__20151117T131051_V20150703T000000_21000101T000000_B12</GIPP_FILENAME>
</GIPP_List>
<PRODUCTION_DEM_TYPE>S2__OPER_DEM_GLOBEF_PDMC_19800101T000000_S19800101T000000</PRODUCTION_DEM_TYPE>
<IERS_BULLETIN_FILENAME>S2__OPER_AUX_UT1UTC_PDMC_20171207T000000_V20171208T000000_20181207T000000</IERS_BULLETIN_FILENAME>
<GRI_List/>
<ECMWF_DATA_REF>S2__OPER_AUX_ECMWFD_PDMC_20171211T000000_V20171211T090000_20171211T210000</ECMWF_DATA_REF>

</n1:Auxiliary_Data_Info>

As far as I can tell, the relevant schema is .snap/auxdata/Sen2Cor-2.4.0-Linux64/lib/python2.7/site-packages/sen2cor/cfg/S2-PDGS-TAS-DI-PSD-V14.2_Schema/DICO/14/PDGS/dimap/dimap2A.xsd

		<xs:element name="PRODUCTION_DEM_TYPE" type="xs:string">
			<xs:annotation>
				<xs:documentation>Reference to used DEM</xs:documentation>
			</xs:annotation>
		</xs:element>
		<xs:element name="IERS_BULLETIN_FILENAME" type="xs:string">
			<xs:annotation>
				<xs:documentation>Reference to IERS Bulletin</xs:documentation>
			</xs:annotation>
		</xs:element>
		<xs:element name="GRI_FILENAME" type="xs:string">
			<xs:annotation>
				<xs:documentation>Reference to GRI data </xs:documentation>
			</xs:annotation>
		</xs:element>
	</xs:sequence>

I cannot find the code that emits GRI_List - and it does not always appears in the file. It does cause a validation error against the schema