I've created a simple short lived process in Workbench ES2 and tried to use process_data/@id as unique identifier as I used in Workbench ES.
When I invoke the process in a workbench this id always returns -1.
There was some change in transition from ES to ES2 that I'm not aware of?
I wonder exactly the same question as you ...
I try to identify the user's workspace to pre-fill a form to load.
And I always obtain the id value -1...
Did you find an answer to your question ?
Wrong way ?
Does your process is a long or short lived?
Last time I've noticed that short lived returns -1 and long lived returns
unique process id.
is a short-lived ...
I will try with a long-lived.
Thank you, I will give my comments.