After updating my website to WordPress 5.0 I cannot use Page Builder anymore. How can I get it back?

WordPress 5.0 introduces a new editor for the content named Gutenberg.

We’ve been using a Page Builder by SiteOrigin┬áplugin for years in our themes and all our themes rely on it. For the time when we’re migrating our themes to be Gutenberg-compatible, you can get the old classic editor experience with Page Builder by installing the Classic Editor official WordPress plugin.

TIP: If you’ve never installed a WordPress plugin before, here is a quick guide.