I have a WordPress installation on AWS and I was facing an issue that authors are not able to submit content like media in one go and a time-out error occurs. After refreshing the page 5-6 times authors are able to upload content again.
To mitigate this issue, I deactivated all the plugins and upgraded to WordPress 4.0 from the back-end, which also raised a problem and I had to rerun the update manually.
So I downloaded the latest WordPress Zip and followed the instructions as mention on http://codex.wordpress.org/Updating_WordPress.
Finally, in the last step, when I refreshed the browser window, it asked that the database needs an upgrade too. So I followed the on-screen instructions and logged into my WordPress.
After logging in, the WordPress back-end looks like in the following screenshot:
It looks as if no CSS being loaded. How can I solve this issue?