Hello,
I'm using the AGRIBALYSE database and i'm trying to create a product system for this process. It's in my interest that the reference unit is "Oil separator sludge" but every time the reference unit is a input i get this error message: "No process with valid reference product output or waste input selected". What am i doing wrong?
The process can be seen below.
That's the error message
Thank you all in advance.
