Thanks for the tips!
I’ve tried all of the above, except for the last point. But if it’s all working in other browsers, the wp-admin and wp=includes folders must be OK, right?
What technology is used for the dropdown animation when I click ‘status’, ‘visibility’ or ‘publish’? I’m getting the feeling the problem has got something to do with that. Because my URL does change after clicking EDIT, but the dropdown simply doesn’t start. Besides that, I’ve discovered that the button for uploading media is also not responding. The ‘media pop-up’ won’t show. Sometimes it does open, but if it does, it does so in a new tab. Strange right? As if rich animations like dropdowns and pop-ups don’t want to show…