Map Editor Bug Report

Was working on attempting to add PBR to Rally Forest, saved the map's progress (not much) and closed the game. Came back later, loaded up the map, and tried to Reload Terrain Materials in the Terrain Material Library, leading to this lovely block of red text in the console:


Most likely mod related, but I've never encountered this before and my mods haven't changed prior to this error string, which combined with the errors originating within the Reloading Terrain Materials LUA code leads me to believe it's some strange edge case error unrelated to mods.

Perhaps this was or is the wrong place to post this, but as I'm not 100% sure of the nature of the bug I figured this would be the best place.

Cheers!