I have (or had) the latest version of CoursePress installed including the one that came in overnight.
It has a problem in that it makes Gravity Forms fields uneditable. The field controls no longer appear on old fields and while adding a new field makes them visible, and delete and duplicate will then work, the editing toggle does not.
Deactivating CoursePress returns the functionality.
I'm not sure when the bug developed as I hadn't attempted to edit any new forms since installing CoursePress.