I was working along and out of nowhere one of my post types (on admin bar) said {{labels.menu_name}}. The post types' posts are still discoverable, but the error is causing an inability to delete/edit post types (so I can't just delete it). I am still able to create new ones though, but all posts within the post types do not show up saying "no your-post-type-here found" for "operational" post types and the broken one says {{labels.not_found}}.
This did seem to occur after I enabled comments on the post type post creation. This error is affecting all operations of metabox because I can't edit my custom fields either. I've been trying to find information as to where metabox keeps its data but have unsuccessful. I have checked my database, de and reactivated the plugin and deleted then reinstalled the plugins. There has also been no plugin changes and has never been any issues in the past.