The input and the error output is in the image below. I wonder what does that mean? Thanks in advance. I tried looking for the error online but found nothing. Thanks in advance. 
I have the very similar problem. But my model is defined properly and I can get feynman rules fine.
I am trying to make a ufo for madgraph from my model and here is the error I have attached.
I would appreciate any help. Im clueless.
I have the answer, first of all LNew for your case or LDM for mine is showing in Blue, that it means it is not defined yet. So, you have to define it first. You can define it in either Mathematica or in the .fr file. After having done that, from evaluate quit local kernel, and then rerun all the commands.
Hope this helps :)
I also am facing the same problem here, here is my part of the code:
I also have the same error- has anyone found an answer?
I tried again I don't know if you can see it better. I am pretty new to mathematica but there seems to be no easy way of copying and pasting so I uploaded the picture ]
Here is the input if the image still couldn't be uploaded:
Starting Feynman rule calculation.
Expanding the Lagrangian...
Collecting the different structures that enter the vertex
GetFC::Head : Wrong Head in FC.
Your image appears to be missing. If you have Mathematica code, include that, not as an image, but as a code block.