Okay, so I cooked my map successfully the first time through (Although I did it incorrectly and cooked ALL of the levels, not just Persistent Gameplay)
It loaded fine, worked fine, but there was a main clutter layer missing.
Custom Clutter Layer: DeadDriedGrass
Deleted Beach Pebbles, Landscape ID 3
Copied the LayerInfo for both Beach Pebbles and DeadDriedGrass to my mob.
Changed Beach Pebbles to Landscape ID 0 and DeadDriedGrass to 3
Linked the correct layerinfos in the paint tool
Because the clutter layer was not working in-game I found the SM and materials/MICs involved and copied them all to my Mod folder, then relinked them(I did NOT relink the material within the SM itself though. Trying to do so crashes my Dev Kit every time)
On the second and third cook, on startup, the game crashes giving me the attached fatal error.
I am giving the backstory of the clutter layer because the fatal error leads me to believe it is related.
Thank you so much in advance!