Same issues as others with update from 3.9.7 running on latest WP.
It was also the only website that failed to automatically update the plugin that I have on the same server.
I tried deactivating then updating – same thing. So I deleted the plugin and reinstalled without further issue.
Yes I am able to alter the existing css code.
Your server should have log files that you can use. But it sounds like your website host is a waste of space – time to move to a new host and start with a fresh install of the latest version of wordpress and rebuild your database from clean backups.
Been seeing the same thing and it appears it’s from a spambot that is associated with automated spam registrations.
