This message means WordPress couldn't connect to your site's database, where your posts, pages and settings are stored. Until the connection works again, the site can't show any content. On its own, the message doesn't mean your content is gone: usually WordPress just can't reach it.
What you can try
- Reload the page after a short while. A brief interruption can cause this message, and it then clears on its own.
- Think about what changed just before. A common cause is a migration or cloning plugin that replaced your site's database settings while importing a site from somewhere else.
The database and its connection settings are managed on our platform, so there isn't much more to do on your side.
Contact support
Contact support with your domain, when the error started, and anything you changed just before, such as a plugin you installed or a migration you ran. We'll check the database connection settings, repair the database if it's damaged, and restore a daily backup if that's the best fix.