Cause: Error invoking function "JSON"

Hi there,

I’m trying to run a simple process that takes as an input a JSON object.

My BPMN model is rather simple, called master.bpmn and looks like this:

image

Deployment is successfull and I can see the model in my camunda cockpit

The conditon type I’m using for the sequence flow is this one:
${ JSON(customer).prop("age").numberValue() >= 21}

I’m using Postman to start the process using the following command:
localhost:8080/engine-rest/process-definition/key/master/start

The Body of the request is:

{
“variables”:
{
“customer”:
{“value”:{“age”:21},“type”:“json”}
}
}

I get the following:
"message": "Cannot instantiate process definition master:7:6c67214b-f4a5-11e9-b3a5-50eb7136ed6c: Must provide 'null' or String value for value of SerializableValue type 'json'."

When changing the type from json to string, I get the following:
"message": "Cannot instantiate process definition master:7:6c67214b-f4a5-11e9-b3a5-50eb7136ed6c: Error while evaluating expression: ${ JSON(customer).prop(\"age\").numberValue() >= 21}. Cause: Error invoking function 'JSON'".

Could you please give me a hand on this one?

Thx,Ch.