ADF 403 Forbidden - invoke method

If you have a method call as your default activity in a task flow and you get 403 Forbidden http status code is returned (given you have set all the correct permissions in the jazn-data file to your task flow).

Just add the following tag to your taskflow (add the tag in the near the bottom of the enclosing task-flow-definition tag)

<visibility><url-invoke-allowed/></visibility>

Or you can  click on the task flow overview, visibility, URL Invoke section for the same result