last version problem

Do you, by chance, have what the critical error message was? The plugin input field warnings are due to the migration script not running properly on your install (for some reason), which the critical error message may point to what is causing that (I’m tracking this problem as part of this GitHub issue https://github.com/mtekk/Breadcrumb-NavXT/issues/263). Also, looking at the settings that are getting complained about, my guess is you may be experiencing something similar to this issue as well: https://wordpress.org/support/topic/php-fatal-error-on-plugin-settings-page/ (GitHub issue: https://github.com/mtekk/Breadcrumb-NavXT/issues/262)