Segmentation fault error while printing normElastEnergy()

In my simulation I wanted to print the normal elastic energy values at particular intervals. I use Law2_ScGeom_MinlinPhys_Mindlin() model for contact. But when I try to get the Energy values using the command Law2_ScGeom_MindlinPhys_Mindlin().normElastEnergy()
in python script, I get segmentation fault.
Please suggest a solution for this issue