here is the workflow I've followed:
I've tested the same workflow with the same data in two different environments:
Unfortunately the job must be done using 2.9.5.
Any idea?? Is it a bug?
Actually, the first time I've activated both the batch rules and the result of the evaluation was the 999999 error.
So then I've tryed to evaluate the two rules separately in order to better understand where the error occurs and I've discovered that the error was during the evaluation of the Pipe Connection creation and snapping rule.