I tried to add a module for electricity generation. I added a coal plant with feedstock resource "Coal Bituminous". But when I try to see the results it gives the error as shown in the attachment. In the resources, the variable is undefined.

What should I do?

Can you tell us exactly when the error occurs? Does it happen when you add the process? View results? Another situation?

Also, was Coal Bituminous consumed or produced at any other branches before you attempted to add it into your module?

Thanks,

Taylor