Epic link is not visible on Create/Edit

The Epic link field is not visible on the create and edit link for an issue, even though it is on the associated screens and configured for all projects and issue types. The Where's my field? also indicated is should be on the screen.
But as you can see in the attached, it's not.

We had planned to use this to associate an issue to a link based on the feedback we received on the forums.

1) Why do the fields not show up if they are configured to?
2) Can this field be used to associate an issue to an epic?