Adding party relationship roles - error message is confusing.

Error trying to begin transaction, could not process method: The current transaction is marked for rollback, not beginning a new transaction and aborting 
current operation; the rollbackOnly was caused by: Failure in create operation for entity [PartyRole]: org.ofbiz.entity.GenericEntityException: Error while 
inserting: [GenericEntity:PartyRole][createdStamp,2010-01-11 14:04:02.002(java.sql.Timestamp)][createdTxStamp,2010-01-11 
14:04:01.966(java.sql.Timestamp)][lastUpdatedStamp,2010-01-11 14:04:02.002(java.sql.Timestamp)][lastUpdatedTxStamp,2010-01-11 
14:04:01.966(java.sql.Timestamp)][partyId,100001(java.lang.String)][roleTypeId,_NA_(java.lang.String)] (SQL Exception while executing the 
following:INSERT INTO OFBIZ.PARTY_ROLE (PARTY_ID, ROLE_TYPE_ID, LAST_UPDATED_STAMP, LAST_UPDATED_TX_STAMP, CREATED_STAMP, 
CREATED_TX_STAMP) VALUES (?, ?, ?, ?, ?, ?) (INSERT on table 'PARTY_ROLE' caused a violation of foreign key constraint 'PARTY_RLE_PARTY' for 
key (100001). The statement has been rolled back.)). Rolling back transaction.org.ofbiz.entity.GenericEntityException: Error while inserting: 
[GenericEntity:PartyRole][createdStamp,2010-01-11 14:04:02.002(java.sql.Timestamp)][createdTxStamp,2010-01-11 14:04:01.966(java.sql.Timestamp)]
[lastUpdatedStamp,2010-01-11 14:04:02.002(java.sql.Timestamp)][lastUpdatedTxStamp,2010-01-11 14:04:01.966(java.sql.Timestamp)]
[partyId,100001(java.lang.String)][roleTypeId,_NA_(java.lang.String)] (SQL Exception while executing the following:INSERT INTO OFBIZ.PARTY_ROLE 
(PARTY_ID, ROLE_TYPE_ID, LAST_UPDATED_STAMP, LAST_UPDATED_TX_STAMP, CREATED_STAMP, CREATED_TX_STAMP) VALUES (?, ?, ?, ?, 
?, ?) (INSERT on table 'PARTY_ROLE' caused a violation of foreign key constraint 'PARTY_RLE_PARTY' for key (100001). The statement has been rolled 
back.)) (Error while inserting: [GenericEntity:PartyRole][createdStamp,2010-01-11 14:04:02.002(java.sql.Timestamp)][createdTxStamp,2010-01-11 
14:04:01.966(java.sql.Timestamp)][lastUpdatedStamp,2010-01-11 14:04:02.002(java.sql.Timestamp)][lastUpdatedTxStamp,2010-01-11 
14:04:01.966(java.sql.Timestamp)][partyId,100001(java.lang.String)][roleTypeId,_NA_(java.lang.String)] (SQL Exception while executing the 
following:INSERT INTO OFBIZ.PARTY_ROLE (PARTY_ID, ROLE_TYPE_ID, LAST_UPDATED_STAMP, LAST_UPDATED_TX_STAMP, CREATED_STAMP, 
CREATED_TX_STAMP) VALUES (?, ?, ?, ?, ?, ?) (INSERT on table 'PARTY_ROLE' caused a violation of foreign key constraint 'PARTY_RLE_PARTY' for 
key (100001). The statement has been rolled back.)))

    <simple-method method-name="createPartyRelationship" short-description="createPartyRelationship">
        <if-empty field="parameters.roleTypeIdFrom"><set field="parameters.roleTypeIdFrom" value="_NA_"/></if-empty>
        <if-empty field="parameters.roleTypeIdTo"><set field="parameters.roleTypeIdTo" value="_NA_"/></if-empty>
        <if-empty field="parameters.partyIdFrom"><set field="parameters.partyIdFrom" from-field="userLogin.partyId"/></if-empty>

        <if-empty field="parameters.fromDate"><now-timestamp field="parameters.fromDate"/></if-empty>

        <!-- check if not already exist -->
        <entity-and entity-name="PartyRelationship" list="partyRels" filter-by-date="true">
            <field-map field-name="partyIdFrom" from-field="parameters.partyIdFrom"/>
            <field-map field-name="roleTypeIdFrom" from-field="parameters.roleTypeIdFrom"/>
            <field-map field-name="partyIdTo" from-field="parameters.partyIdTo"/>
            <field-map field-name="roleTypeIdTo" from-field="parameters.roleTypeIdTo"/>
        </entity-and>

<!-- MORE HELPFUL ERROR MESSAGE START -->
		<if-compare field="parameters.roleTypeIdTo" operator="not-equals" value="_NA_">
			<entity-one entity-name="PartyRole" value-field="lookedUpToPartyRole">
				<field-map field-name="partyId" from-field="parameters.partyIdTo"/>
				<field-map field-name="roleTypeId" from-field="parameters.roleTypeIdTo"/>
			</entity-one>
			<if-empty field="lookedUpToPartyRole">
				<!-- TODO : read this message from a resource file -->
				<set field="failMessage" value="You have tried to assign a &quot;to role&quot; of '${parameters.roleTypeIdTo}', but party ID ${parameters.partyIdTo} does not have a '${parameters.roleTypeIdTo}' role.  "/>
				<string-append field="failMessage" string="Use the Role(s) screen for party ID ${parameters.partyIdTo} to first assign the '${parameters.roleTypeIdTo}' role to them."/>
				<add-error><fail-message message="${failMessage}"/></add-error>
			</if-empty>
		</if-compare>

		<if-compare field="parameters.roleTypeIdFrom" operator="not-equals" value="_NA_">
			<entity-one entity-name="PartyRole" value-field="lookedUpFromPartyRole">
				<field-map field-name="partyId" from-field="parameters.partyIdFrom"/>
				<field-map field-name="roleTypeId" from-field="parameters.roleTypeIdFrom"/>
			</entity-one>
			<if-empty field="lookedUpFromPartyRole">
				<!-- TODO : read this message from a resource file -->
				<set field="failMessage" value="You have tried to assign a &quot;from role&quot; of '${parameters.roleTypeIdFrom}', but party ID ${parameters.partyIdFrom} does not have a '${parameters.roleTypeIdFrom}' role.  "/>
				<string-append field="failMessage" string="Use the Role(s) screen for party ID ${parameters.partyIdFrom} to first assign the '${parameters.roleTypeIdFrom}' role to them."/>
				<add-error><fail-message message="${failMessage}"/></add-error>
			</if-empty>
		</if-compare>
		<check-errors/>
<!-- MORE HELPFUL ERROR MESSAGE END-->

        <if-empty field="partyRels">
            <make-value value-field="newEntity" entity-name="PartyRelationship"/>
            <set-pk-fields map="parameters" value-field="newEntity"/>
            <set-nonpk-fields map="parameters" value-field="newEntity"/>
            <create-value value-field="newEntity"/>
        </if-empty>
    </simple-method>