I just ran into this same problem. I’ve disabled all other plugins, tried changing themes (to twentyeleven), tried deleting and then reinstalling Elementor and Elementor Pro using the latest released files – all of these had no effect.
One page take a very long time for the editor to load – in Chrome about 2 mins, in FireFox about 1 min. I’ve submitted a ticket with Elementor support. Waiting to hear back.
