I'm still trying to edit the navigation page... The founder of the wiki made me an admin, so now I've got a "Edit wiki navigation" line in the "Contribute" pop-up menu, and when I'm on the navigation page editor, I can edit it but I can't save nor publish the page...

And when I go directly on the navigation page, I still can't access the editor. The "Edit" menu only shows "History" and "Delete".

Could someone please help me find what is missing for me to edit and publish the navigation page?