Help me to fix my code of custom alfresco workflow i try to use exclusive gateway in my workflow but i got error: .activiti.engine.ActivitiException: Unknown property used in expression: ${trwf_reviewOutcome == 'Approve'}.

I using alrefsco SDK 4.8.0. I did foloww instrcutions .html but everything is work fine but in exclusive gateways got some troubles for developing.

Workflow Model

<type name="trwf:activitiReviewTask">
    <parent>bpm:activitiOutcomeTask</parent>
    <properties>
        <property name="trwf:reviewOutcome">
            <type>d:text</type>
            <default>Reject</default>
            <constraints>
                <constraint name="trwf:reviewOutcomeOptions" type="LIST">
                    <parameter name="allowedValues">
                        <list>
                            <value>Approve</value>
                            <value>Reject</value>
                        </list>
                    </parameter>
                </constraint>
            </constraints>
        </property>
    </properties>
    <overrides>
        <property name="bpm:outcomePropertyName">
            <default>{.0}reviewOutcome</default>
        </property>
    </overrides>
</type>

Workflow BPMN

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns=";
             xmlns:activiti=";
             xmlns:xsi=";
             targetNamespace=";>

    <process id="billPayProcess" name="Bill Pay Process">
        <!--TASK SEQUENCE-->
        <startEvent id="startEvent"
                    activiti:formKey="trwf:submitHelloWorldTask"
                    name="StartSubmitTask"/>
        <userTask id="validationPayBillUserTask"
                  name="BillVarificationStep"
                  activiti:assignee="admin"
                  activiti:formKey="trwf:activitiReviewTask">
            <extensionElements>
                <activiti:formProperty id="tr:reviewOutcome" type="string" required="true"/>
            </extensionElements>
        </userTask>
        <exclusiveGateway id="exclusiveGw" name="Exclusive Gateway" default="flow5"/>
        <userTask id="approvalTask"
                  name="ApprovalTask"
                  activiti:assignee="admin"
                  activiti:formKey="trwf:approvalTask" />
        <userTask id="rejectTask"
                  name="RejectTask"
                  activiti:assignee="admin"
                  activiti:formKey="trwf:rejectTask" />
        <endEvent id="endEvent"/>

        <!--SEQUENCE FLOW-->
        <sequenceFlow id="flow1"
                      sourceRef="startEvent"
                      targetRef="validationPayBillUserTask"/>

        <sequenceFlow id="flow2"
                      sourceRef="validationPayBillUserTask"
                      targetRef="exclusiveGw"/>

        <sequenceFlow id="flow3" sourceRef="exclusiveGw" targetRef="approvalTask">
            <conditionExpression xsi:type="tFormalExpression">
                <![CDATA[${reviewOutcome == 'Approve'}]]>
            </conditionExpression>
        </sequenceFlow>

        <sequenceFlow id="flow4" sourceRef="exclusiveGw" targetRef="rejectTask">
            <conditionExpression xsi:type="tFormalExpression">
                <![CDATA[${reviewOutcome == 'Reject'}]]>
            </conditionExpression>
        </sequenceFlow>

        <sequenceFlow id="flow5"
                      sourceRef="rejectTask"
                      targetRef="endEvent"/>

        <sequenceFlow id="flow6"
                      sourceRef="approvalTask"
                      targetRef="endEvent"/>
    </process>
</definitions>