2147.797 Error MainLoop.cpp:1451: Exception at tick 34992283: The mod Belt Balancer 2 (2.0.9) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event belt-balancer-2::on_player_mined_entity (ID 69)
__belt-balancer-2__/objects/balancer.lua:140: attempt to index local 'stack_belt' (a nil value)
stack traceback:
    __belt-balancer-2__/objects/balancer.lua:140: in function 'recalculate_nth_tick'
    __belt-balancer-2__/objects/part.lua:321: in function 'remove'
    __belt-balancer-2__/control.lua:145: in function <__belt-balancer-2__/control.lua:134>

Also

Error while running event belt-balancer-2::on_robot_mined_entity (ID 68)
__belt-balancer-2__/objects/balancer.lua:140: attempt to index local 'stack_belt' (a nil value)
stack traceback:
    __belt-balancer-2__/objects/balancer.lua:140: in function 'recalculate_nth_tick'
    __belt-balancer-2__/objects/belt.lua:362: in function 'remove_belt'
    __belt-balancer-2__/control.lua:149: in function <__belt-balancer-2__/control.lua:134>