Deactivated theme. Reactivated and all grids are gone.
When I attempt to view grid page I get a "Nothing found."
How can I fix this?
by deactivating theme none of your content should be deleted, not posts/pages or Theme Settings. So if you just deactivated theme and didn't do anything else you should be good.
Try refreshing your permalinks: Settings -> Permalinks and just hit "save" button.
If that fails share your WP login credentials so I can take a closer look (just mark your reply as "private").
Your suggestion of refreshing the permalink structure worked beautifully!
Thank you for your help!