When adding a new WordPress Post or updating an existing WordPress Post you get the following error:
Publishing failed. You are probably offline.
This might happen if you use Cloudflare for your SSL.
To fix do the following:
From WordPress Admin click on Settings > General
Check that the WordPress Address (URL) and Site Address (URL) are the same as what you see in the browser address bar:
Browser address bar:
Hint: You might be missing the S after http:// e.g. if the WordPress Address is showing http://www.yourdomain.com change this to https://www.yourdomain.com