How can I set true/false with a map when using a Mutator Zone

[DustinREDGames]

The “decides” effect means it needs to check if the value change will be valid. Potentially the Player could be null or your map is empty, etc… So it needs to be in an if condition.

So try this:

if (set PlayerEnterMutZone[Player] = true):
    # it worked, continue...