nova fulcrum
I've tested this a bit to help narrow it down a little.
IF I am Shift-Click dragging (Left or Right click)
AND I have selected more than a few foundations
AND autosave starts
THEN the game will crash.
This is 100% repeatable for me.
I had no crashes during testing if I had only a single 1x1 foundation selected.
My autosaves take ~7 seconds to complete. Perhaps this is contributing.
I used the attached blueprint for testing as items to copy/delete during the autosave.
tiny gazelle