Numbers upgrade - can't find field to edit!
Sorry if I'm being dense here, I'm sure there's an obvious answer that someone here will know but I just cannot fathom it nor find any info already online.
I've just upgraded from Mountain Lion to El Capitan. I then upgraded an earlier Numbers spreadsheet to edit it in El Capitan. After editing I printed it and a field I can't see anywhere on the new version, or find any way to access, comes out on the printed copy (immediately above the table and is text on 2 lines).
I believe this field used to be editable in Mountain Lion in a sidebar on the left, but I don't remember the name of it so I can't look up how to access it in the upgraded version. I do know, however, it's not the table name or sheet name because I can see where to edit those.
Can anyone kindly help me find how to access this hidden field so that I can edit it?
In advance, many thanks for sharing your expertise and ideas.
Jackie
Numbers 3.6.2-OTHER, OS X El Capitan (10.11.6)