@Galen Helfter O
Yes, this one is really strange. I have tried to reproduce it on another PC as well (one of my render nodes with the same other plugins installed, but starting 3ds Max as trial then), but there it worked fine. Still, the only installation difference between a working and a non-working SME in 3ds Max 2019 on my workstation is the installation of the substance plugin.
For what it is worth, here are my system specs:
i7-5930K, 64 GB RAM, GTX 1080
Windows 10 Pro 1709
3ds Max 2019.1 (21.1.0.1314) on maintenance plan, Forest Pack, RailClone, Vray, Phoenix, Clone, Greeble, Bercon Maps, Labyrinth, RPManager, Soulburn Scripts
Substance Player 2018.1.2, Substance Designer 2018.1.2
3ds Max 2016 with the same plugins
Adobe stuff (PS, AE, AI etc.)
What else could I do or tell you to find or fix the problem?
Thanks,
Bob