missing field in contact form

[Wingfield]

hello,

I'm entering contacts and all of a sudden the "first" name field is gone. I can't see the "first" name in the form. if I click the arrow it shows that "first" name is checked. in fact, I can not uncheck it. any idea how to fix this??

you can see in the attachment that even though this contact has a "first" name, there's nowhere on the form to change / edit the "first" name field.

any help appreciated.

David