After you picked the head model by pressing Pick Head button in the Create Rig and Skin window, script analyzes your model and shows BonyFace Head Test window with test results: if OK button is active then it's all right, press it to move back into main window and continue, but if OK button is not active then you have to close this window (or press Cancel button) to undo pick head and fix your model before picking again.

Left picture shows unpassed test, right picture - passed. To pass the test model must meets some requirements are showed in Requirements (all must be green) group - a color of all rectangles there should be green, then OK button will be active, that's automatically means the test was passed successfully, but if some rectangles are red then you have to fix these items.

    A list shows all items one by one in correct order from top to bottom with recommendations of how to fix them:
  1. Correct Name: name should contain only chars A-z, 0-9 and _ - rename your head model
  2. Editable Poly - convert to Editable Poly or add Edit Poly modifier
  3. Head Position: model should be above world XY plane - move your model up
  4. Head Orientation: model should look directly at you in Front viewport - axes of pivot points must be parallel to world axes, rotate pivot or model depending on your situation
  5. Head Scale: scale should be 100% at all axes (use ResetXform to fix) - use Command Panel > Utilities > Reset XForm and then collapse modifier stack
  6. Unempty Skin Modifier: add some bones into skin modifier first - there are no bones in applied Skin modifier, it is inappropriate, remove Skin at all or add bones into it
  7. Separate Skin Modifier: skin modifier should be applied only on a single head object - Skin is applied on some another object(s) besides the head (name is written with italic font in modify panel), it is inappropriate, remove Skin at all or apply it only to the single head mesh (or to a character if it is a single mesh)
Warnings group shows possible problematic parts of the mesh where you would have troubles in future. First item check topology by calculating percentage of non-quad polygons (lesser number is better), second item calculates elements - an independent parts of the mesh, for example some users create eyelashes, mustashes, geometry at eye corners and puts this all into elements, but this would be a possible problem at autorig and autoskin phases, BonyFace may be freezed or crashed because of unwelded vertices.

Additional objects was found (clear checkboxes to pick later) group shows additional objects were found by script itself as appropariate parts of the head. This is useful if it found such objects correctly, so you don't need to pick these objects by yourself, but if not then you may turn off some checkboxes or press Clear All button to skip all objects and pick them up later manually in main window.

At the end press OK button if all is right or Cancel button - if not.