We have created a single long page in the pro theme. Several times throughout the build and right now the page cannot be saved. The workaround we had been using was to save the entire page as a template, create a new page, and put the template in. Also, WP-All in one migration is not able to create backups of the site now. We did not expect assistance with a third party plugin, but it may be helpful to know while investigating.
Please investigate this issue. We will provide login credentials and instructions in recreating the error in a private message. The plugins we are currently using are: All-in-One WP Migration, Classic Editor, Layerslider WP, and Wordfence Security.