Problem with mesh interfaces
 

Hi guys, i got a problem with ansys fluent while setting up.
As i attached the image, mesh interfaces seems not activated.
My simulation is a simple heat exchanger having two interfaces of shell to tube and tube to tube fluid. Please help
Attachment 50671

How many is there solid in your simulations? look at the design moduler

If connections and contacts are defined properly in meshing you dont need to define them in fluent and mesh interfaces doesnt activate.