I discovered that an iframe had been added to one of the template files for the side bar, and it had an improperly closed iframe element tag. This caused the browser to “guess” how to close the html.

I would hunt through all the code, and also look for visual weirdness on pages that have this issue. You should let Nationbuilder load the Jquery library for you, since they may be running code, that only works with their chosen version.

I’ve been having this problem a lot lately — One minute, nationbuilder will be loading jquery just fine, the next, none of it works (but the site starts working again if I include jQuery myself). Any insight as to why that might be happening?

Or jquery library is corrupted, or an incompatible version…