mobs don't spawn at night

The Aternos forums are now deprecated

Learn more about this change here.

For help regarding Aternos, we recommend you to visit our support center.

    I was skyblocking with a friend and I noticed that no monsters spawned. It was night and I checked where the brightness level was and (where there is no roof) 15 for sky and 0 for block. Can someone help me, because we can't make farms?