BuddyPress.org

I was having the same problem. It was being caused by the javascript/ajax files for “BuddyPress Theme Compatibility” plugin.

I solved the problem by going to Appearance > BP Compatibility, then scrolling down to the bottom of the page and clicking “finish”. That step only has to be done after you first activate the plugin. On the page that comes up, check the box for “Disable BP Template Pack JS / AJAX” then click “Save Settings”.

That solved the problem for me.