Rahul Kumbhar
Ansys Employee

The reason is that you have a contact defined on that face and that face doesn't have any mesh since it defeatured away. Check the defeaturing tolerance, set the value such so that mesh can walk over unnecessary features and avoid higher mesh count but smaller than the features you want to capture properly like bolt holes, fillets etc. If you have few contacts, you can do visual inspection for contact with no mesh.