cyclical data detected, l parametre is recursive

the definition always  worked very well with the refered object in rhino, and i kept changing the shift  value to see different effect. i didnt do anything else to  the definition and the object, but the definition couldnt generate anymore the result suddenly when i chose the boolean as false as i always did, but if i chose true, it worked but not the effect i want. and all the components are grey,means that it works ? but without result! and i found blow the message of cyclical date dected, L parametre is recursive, but one second  before, all works quite well!  i tried also copying the object to other layers and redoing the definition again,but no luck.

cheers,

wei