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？
7 W1 [2 ]4 Y5 X0 s& F
conveyor元素的input rule：
if nparts(coneyor001)<5
& ]  o: y3 l. I& L# e$ p/ }, xpull from buf1 with labor1 using path
else
* y6 M. a- x' d& J( S( [5 ~wait
endif