Define grid interface
 

Hello every one!
I am simulating a pitching airfoil in fluent!I defined a circle around the airfoil and applied the motion to the circle!So I defined two edges as interface!
First I had a problem with walls which automatically were created by fluent when I defined grid interfaces!I solved this problem by selecting periodic! now when I want to initialize the problem, unfortunately it gives me an error:

Error: no periodic zones adjacent to grid interface
Error Object: ()
Does anyone knows the solution?!