problem with meshing an enclosed airfoil
 

i'm trying to simulate a 3d airfoil using naca0012 coordinates.
But whenever i try to mesh the system it gives an error stating that the following geometry cannot be meshed in the given quality. I've tried everything by changing the quality from fine to coarse but of no use.
Can someone help me with this. I'm very new to this software.:confused:

PS: i'm unable to attach my geometry file, if anyone can try meshing it plz pm me ur email id.;)