I apologize for cross posting this. My initial discussion:http://www.concrete5.org/community/forums/customizing_c5/concrete-5... has elicited zero responses.

I am attempting to add an "exclude from nav" page property to a page. I have tried using the Dashboard Sitemap as well as the dropdown directly on the page: edit-->Page Properties.

In both instances I get a mystery pop-up (screen shot attached,) showing page source, (markup.) Console seems to show a jQuery error. Further details are in my original post, (above.)

The site seemed to work ok prior to the update. I have tried further trouble shooting by:

1. Changing to plain yogurt -- still broken, so it's not the theme
2. Replaced the Concrete 5.6.2.1 core files -- still broken
3. Tried commenting out lines in the .htaccess that relate to JS compression -- still broken

Thanks in advance for any suggestions! (New to the forums, C5 user for a couple of years)