After domain assign, lightbox will not load images

I recently built a client site in a folder, and when they approved it, I assigned their domain to the folder as an Add-on domain. As usual in this situation, I have to chase down a lot of urls that still have the old, temporary path, not the final path. In this case, I was using a domain called, so the work site address was originally

Now that I’ve made it live, we simply use I’ve run into an issue where images in posts and groups won’t open in lightbox, and I can’t really add new ones in BuddyPress. Standard WordPress works fine. When I look at the error log, I see this:

XMLHttpRequest cannot load No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘’ is therefore not allowed access.

SO i can see that Buddypress/RTMedia has, somewhere, the wrong/old url path. But I can’t find where to fix this. Any suggestions?

Wordpress 4.3.1 Bbpress 2.5.8 BuddyPress 2.3.4 rtMedia 3.9