ExtendScripts JSON object is suddenly undefined?

I´m not sure since which PPro version the JSON object is supported in Extendscript but I never trusted it. I definitely recommend to stringify your data manually.

I used to do it this way:

var obj = '{';

  obj += '"type":"bin",';

  obj += '"age":"'+current_age+'",';

  obj += '"name":"'+encodeURIComponent(item.name)+'"';

  obj += '}';

For arrays it´s much simpler:

var arr = ["one", "two", "three"];

var string = '['+arr.join(",")+']';

Definitely encode strings that you don´t have control over.

Also, please check if you can implement a listener coding pattern which uses CSXSEvents. On Extendscript you pass it a stringified object and get a parsed object back on the HTML5 listener side. This avoids JSON.parse() on the HTML side.

I hope this helps.

Thomas