When I try to insert a link using the TinyMCE link plugin all that happens is I get an empty popup box.
It continuously tries to load:
tiny_mce/utils/mctabs.js
tiny_mce/utils/form_utils.js
tiny_mce/utils/validate.js
tiny_mce/themes/advanced/js/link.js
I’ve seen solutions where you need to edit a config.php file, but I only have the JS version of TinyMCE
It happens to me all the time in Opera, but not in other browsers. Try refreshing the empty popup you get and you’ll probably get its contents.