NextGEN Gallery: Will not create new galleries

I am trying to restore my NGG tables from a backup, but when I do, even though those restored galleries and photos are functional again, I lose the ability to create new galleries and to add new images to existing galleries.

When I attempt to add a gallery, it is created on my server, but Nextgen does not recognize it. The backup is from a previous version (though I don’t remember which) of Nextgen and someone suggested it may be a database issue with a reference to the older version in the backup preventing the new one from working. I don’t know where to look. I’ve tried to ask for help several places, but no avail…only other people with a similar problem. Anyone have a suggestion? Thanks. ~C