WordPress Speed Up Service | WordPress Website Maintenance Packages Error establishing database connection, after WP upgrade then restoring back-up., by jentelam Hey Support I was updating a website from a customer to the 4.9 version. Before that I made sure to make a back up. After experiencing some issues (some of the widgets weren’t reacting), I decided to restore the back up of earlier this morning. After that, the site went blank and gave the “Error establishing a database connection” message. I still have the back up file if this would be useful. I would love to have this resolved today, so any help coming my way would be greatly appreciated. This website was for one of our customers, so you can see why I’m a bit concerned. Should I contact my hosting’s support for this? Error establishing database connection, after WP upgrade then restoring back-up.