When I Mark the seams of the head mesh. And when I start UV unwrapping. It doesn't show it on UV Editing window.
- Select your object, press Tab to enter Edit mode.
- Press A to select everything.
- If there's any image opened in UV / Image Editor, click "X" button in the menu header. This will unlink image from UV / Image Editor (the image still will be present in the file).
If the model was unwrapped, the UV map should now show up.