Real names on Registration

V4.1.19

I've recently had installed V4.1.19 and also the useful add-on which displays users real names against all their posts.

But I've now lost the registration requirement for people to supply their real names.

This was useful in detecting spammers, and longer term to have newer members' real names included against all their posts. 

Is there any way to re-instate this?

Thanks in advance