Cannot add RedbackMaterial in peacock

[jing-chen1122]

Peacock experienced crashing when opening or adding RedbackMaterial. Please see any fixing to this issue.

[pou036]

We did notice this problem occurring in the past, but not necessarily in a consistent or reproducible manner. It probably has to do with a bug in initialisation somewhere. Unfortunately, we never invested the time to fix this issue.
Often, running peacock a second time (after a crash) allows to proceed...
If you are willing to look into the problem and propose a Pull Request, it would be a great contribution.