I'm trying to change the header image but the settings area is blank. I've attached a screenshot. All the settings options are likewise blank. What could be wrong?
Thanks,
Ellen

Are you really on Atahualpa 3.7.3? release 3.7.3 was released December 14 2011
The last release was 3.7.24 so you are 21 releases behind and the release you are using is almost 8 years old...

Are you using a current release of WordPress or is it 8 years old too?

Backup everything - database and all files so if anything goes wrong you can recover to where you are today. Then install the latest version of Atahualpa but be warned, there might be some issues after all, that is a huge jump in releases...