I’m not sure what you mean about disconnecting that function, because then the GridManager will never be activated, so I didn’t try that yet.
But in the pic below, the top group of errors is what I get if I start the game, and immediately exit it without actually doing anything.
The lower one is if I actually play through the scenario (2 player units vs 3 enemy units, enemies won). It does work in game just fine though, which is weird I guess.
If you want, I could upload the game or something, but other than adding those Blueprints to spawn the buildings, I haven’t altered anything.