Error Code:cannot create surface from sliding interface zone
 

Hi,
I am new to Fluent, and i am currently simulating a 2D wind turbine. I am using sliding mesh method. I had created two region, a rotating region in the middle, and a boundary region which is outside of the rotating region. I have set the circumference of the rotating region as 170mm in diameter, and the circumference of the boundary region as 170.01mm in diameter. After the meshing, when i export it into Fluent, the setup shows "Cannot create surface from sliding interface", and there are two new interfaces appeared in my boundary condition tab, rotating contact region and boundary contact region. :confused: when i click the "Mesh Interface", there is a "contact region" in it. Any advice is very very much appreciated. I am having trouble with this for a long time now.