via wptavern.com => original post link
WordPress 5.9 beta 4 was released this week with fixes for 20 bugs since beta 3. There are a few important changes to note in this release regarding how the WordPress admin will direct users who are exploring block themes.
Prior to a fix in beta 4, it was possible for users to switch to a block theme within the Customizer. This has been changed so that users will see a banner notifying them that the block theme is incompatible, if they try to switch within the Customizer. Here’s the commit message:
Starting in 5.9, block themes are not compatible with (do not support) Customizer; rather, they use the Site Editor. Viewing installed themes in Customizer, this commit adds an overlay message to alert users and give them a way to activate the block theme. Clicking on the “Activate” button activates the block theme and redirects back to the Appearance > Themes interface, where the user can then enter the Site Editor for customization.