Hi!
The error message is reporting an issue with the DOM node structure, as the plugin tries to move the settings box to it’s correct position.
I have tried to open the page with javascript disabled, and I notied that the checkbox values have a serialized text structure there instead of the vlues, possibly because those are stored differently. Do you happen to use a plugin for checkbox custom field values in the post editor screen? Or are these included with the theme?
I suggest entering these manually instead, as the fields are not stored as a text, but as a serialized array of values instead, which I believe is causing the problem here.