Right after every theme and plugin updates, you need to clear your plugin cache, site cache, and regenerate the minified CSS/JS files. This is to make sure that the latest code from the recently installed updates is loaded and not the old cache version. This is most common why the page is not saving after the theme and plugin updates. Now, that your page is saving, you can enable the minify option in your plugin, and then you can test the saving of the page again.
Hope this helps.