WordPress Elements Disappearing

I am having major issues with WordPress and elements disappearing. Can’t figure out what is going on. I was using a plugin, one that I’ve used on other sites and options for it began to disappear. Now I am not even able to add a new page. The “update” button under page attributes is nowhere to be scene.

I would love to know if anyone else is having issues like this. Or I would just as well be grateful for a solution. Reinstalling WP would be a horrible thought, as I would lose weeks worth of work building a customer site.