I am getting exception when I setup the boundary event like below. The format is same as what is present in the documentation https://docs.camunda.org/manual/7.6/reference/bpmn20/events/timer-events/
<bpmn:boundaryEvent id=“Reminder_for_approval_timer” name=“Reminder for approval” cancelActivity=“false” attachedToRef=“approve_task”>
bpmn:timerEventDefinition
<bpmn:timeDuration xsi:type=“bpmn:tFormalExpression”>PT1M</bpmn:timeDuration>
</bpmn:timerEventDefinition>
</bpmn:boundaryEvent>
2018-03-23 09:53:39.429 WARN 5812 --- [nio-8080-exec-8] ExceptionHandler : org.camunda.bpm.engine.rest.exception.RestException: Cannot submit task form 58a10700-2d33-11e8-a83a-185e0f799d42: ENGINE-09026 Exception while parsing cron expression 'PT1M': Illegal characters for this position: 'PT1'
at org.camunda.bpm.engine.rest.sub.task.impl.TaskResourceImpl.submit(TaskResourceImpl.java:127)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
at