Connection lost whilst uploadng

Can’t upload, get this message: “Connection lost. Saving has been disabled until you’re reconnected. We’re backing up this post in your browser, just in case.”
Now it is nothing to do with plugins or any complicated coding error it is clearly a problem with the latest wp update as it happens on both wp.com and wp.org.
Has anyone any ideas. Seen loads of threads saying that problem is resolved – it clearly isn’t.
Thanks
Brian