sliding mesh problem

annie

i want to simulate the unsteady flow of axial compressor. So i must use the tmerge to merge meshes of stator and rotor. I read the merged mesh in Fluent, and want to set the interface between the rotor outlet and stator inlet( rotor in the front of stator), but errors appear: boundaries too far apart.

Who know, what is the problem? The compressor rotates around X axis, in the position of interface, the X position value is completely same. So what is the problem?

Thanks for your help! regards, annie