Can't Find In Error When Creating New Pages

Whenever I try to create a new page, or make changes to the settings of an existing page, I get an error like the following screenshot. If I am editing a page, the error just says "can't find in" and nothing else.  When I create a new page, the error is as in the screen shot.  The new pages are created (or edits are saved), but I need to back to the site content menu before I can access the page again.

It is some sort of server issue. Either an issue updating the site map or something has changed and now there is a conflict with the compression on the server.

You would need to EMAIL me the following to look into it.