Obscure system exception during reconciliation

SystemException: Couldn't evaluate expression ExpressionType(variable=[],evaluator=script:com.evolveum.midpoint.xml.ns._public.common.common_3.ScriptExpressionEvaluatorType@51002c62[code=<null>,language=<null>,returnType=<null>,objectVariableMode=<null>,description=<null>,trace=<null>,relativityMode=<null>,includeNullInputs=<null>,allowEmptyValues=<null>,condition=<null>]): No script code in (new) expression in mapping 'Access role assignment' in template mapping 'Access role (assignment' in objectTemplate:191b00b3-1e2b-4296-a5cb-f756a65d2b5f(User Template - Default)(actor=user:00000000-0000-0000-0000-000000000002(administrator); null=user:f3bb918a-2c4b-4315-9e16-b718fb5b7d95(XXXXX); configuration=systemConfiguration:00000000-0000-0000-0000-000000000001(SystemConfiguration); assignmentPath=null; focus=user:f3bb918a-2c4b-4315-9e16-b718fb5b7d95(XXXXX); iteration=0; memberOf=PPV(String:YYY;d;1478250455000;w;d); user=user:f3bb918a-2c4b-4315-9e16-b718fb5b7d95(XXXXX); operation=modify; iterationToken=; ) in expression in mapping 'Access role assignment' in template mapping 'Access role assignment' in objectTemplate:191b00b3-1e2b-4296-a5cb-f756a65d2b5f(User Template - Default) 

<mapping>
    <name>Access role assignment</name>
    <strength>strong</strength>
    <source>
        <path>extension/memberOf</path>
    </source>
    <expression>
        <assignmentTargetSearch>
            <targetType>c:RoleType</targetType>
            <filter>
                <q:equal>
                    <q:path>c:name</q:path>
                    <expression>
                        <script>
                                <code>
                                    return memberOf.split(";", -1)[0]
                                </code>
                            </script>
                    </expression>
                </q:equal>
            </filter>
            <populate>
                <populateItem>
                    <expression>
                        <script>
                                <code>
                                    return memberOf.split(";", -1)[1]
                                </code>
                            </script>
                    </expression>
                    <target>
                        <path>extension/recStatus</path>
                    </target>
                </populateItem>
                <populateItem>
                    <expression>
                        <script>
                                <code>
                                    import com.evolveum.midpoint.prism.xml.XmlTypeConverter

                                    String val = memberOf.split(";",-1)[2]
                                    if (val == null || val.isEmpty()) {
                                        return null
                                    }

                                    long milis = Long.parseLong(val)
                                    Date date = new Date(milis)
                                    return XmlTypeConverter.createXMLGregorianCalendar(date)
                                </code>
                            </script>
                    </expression>
                    <target>
                        <path>extension/validityEnd</path>
                    </target>
                </populateItem>
                <populateItem>
                    <expression>
                        <value>XXXX</value>
                    </expression>
                    <target>
                        <path>subtype</path>
                    </target>
                </populateItem>
            </populate>
        </assignmentTargetSearch>
    </expression>
    <target>
        <path>assignment</path>
    </target>
    <condition>
        <script>             
                <code>
                    return memberOf != null                        
                </code>
            </script>
    </condition>
</mapping>