I am applying a node to surface contact for the top two plates. No matter what slave or master element I choose, I keep getting this error,

"Error 20211 (STR+211)

reading contact segment data

undefined node # 0

0 0 50 0

input phase will continue if possible"

I am needing help on figuring out what is the best contact between two plates that is being impacted by a projectile? I am needing the two plates to have no separations.

What are some suggesting's and where is this error coming from?