Same issue here, every time I update the server and connect for hte first time I get this error:
Error while running event Big_Brother::on_tick (ID 0)
Big_Brother/stdlib/event/event.lua:77: Big_Brother/control.lua:91: attempt to index upvalue '_ENV' (a nil value)
The next time you connect then it works fine, very strange. Has been this way for months and months. Any fix on the horizon?