I had built my site with the Elemental theme. Recently, I've started working with the Stucco theme. While editing one of my pages, I accidentally closed the window. I had changed the theme to Stucco, but had not yet saved it. I even opened another block and was working on editing that when I was interrupted. Before returning to the task, I closed the window my mistake. My thought was, "crap, I need to redo all that." However, when I logged back in and went to edit the page, I got this message instead:

An unexpected error occurred.
Call to a member function getRootTreeNodeObject() on null

I am not able to edit this page anymore, as the pen, gear, and + symbols are not there. (I can still edit other pages, though.) I tried loading an older version of the page through the sitemap and that did not work either. I still get the same message.

The page that is not working is:http://www.thesleephygienist.com/index.php/blog/daytime-prep-tonigh...

This is what this page is supposed to look like:http://www.thesleephygienist.com/index.php/blog/daytime-prep-tonigh...
(Along the way I was able to duplicate the page with a different URL)

I am running concrete5 version 8.2.1. (I keep getting a 404 error when ever I try to update to 8.4.3, but that's another issue for another day).

Any help would be appreciated. Thanks in advance.