OK – so the plugin is activated which I can see and the tinymce support scripts etc., are being loaded. And while you do have some javascript file concerns I am not seeing any actual errors – although of course as a guest visitor I can’t get through to the edit window anyway.
So that suggests that something you have active on your site is either stopping it from attaching itself to the edit window -or is cancelling it out in some way.
We might need to check each plugin but for starters can you do a very quick test by switching to the WP default theme just to see if that allows it to work.