Enable replicant visibility in old DCRs

System

I am trying to set a replicant visibility to true if the user checks a checkbox. The checkbox ( and hence replicants) are new added feature in my current DCT. The code I wrote works fine on the new data records, but if I try to open old DCRs (which had no checkbox and replicants options), I am getting a null or not an object error. Can anyone throw some light on this?

Thanks