Bug Description

When I plot a universe with multigroup materials, the kernel crashes and the following error is reported:

10:49:11.311 [error] Disposing session as kernel process died ExitCode: 255, Reason: ERROR: Macroscopic can not be used in continuous-energy mode.

Steps to Reproduce

Here is a notebook to reproduce the error
multigroup_MWE.ipynb

Environment

I am running version 0.15.4-dev46 in a conda environment