AI Move To Function [ Failing ]

I am trying to simulate pedestrians in UE4.10. There can be people moving in groups and I plan to achieve that by keeping a 'Leader’of Group( who will determine the path of Group) and rest of the guys(Followers) will follow him.
It seems that the built-in AI MOVE To function fails whenever any Follower tries to call it.

Do you have a Nav Mesh in the scene?

YES… I included nav mesh in the scene…Moreover…The ‘Leader’ of each Group(which is also an AI bot) is walking just fine. ‘Map Index To Location’ function (see in image)…takes reference of Leader and the index( it will be equal to ‘i’…if. The guy is the i_th member of group)…and returns the location… Follower is supposed to move to. For Example: if leader is on location x’,y’,z’…first member of group will move to…x’-150, y’-100,z’