Attempt to add part at undefined sensor 1 on conveyor coneyor001？

dd13616

Attempt to add part at undefined sensor 1 on conveyor coneyor001是怎么回事？

conveyor元素的input rule：
6 _0 ]: ], S7 u) V+ i8 lif nparts(coneyor001)<5
pull from buf1 with labor1 using path
else
wait
endif