STEPS TO REPRODUCE
1. Launch 3DXchange 6
2. Load a random CC Character (e.g. Christian)
3. Select "CC_Base_Teeth" on Scene Tree
4. Go to Modify > Replace Mesh, click "Export Mesh" button, save the OBJ file to desktop
5. Go to Modify > Replace Mesh, click "Replace Mesh" button, load the saved OBJ file, click OK on the pop-up dialog

ACTUAL RESULT
It doesn't work

EXPECTED RESULT
CC character teeth and eye mesh can be replaced correctly