WordPress Core 5.7 and later - Reusable Blocks Disappearing

Resolved in recent versions of WordPress.

In WordPress Core 5.7 and later, while editing Reusable Blocks from within a post, the block content may intermittently disappear. This wipes the content from all instances of this Reusable Block.

Here’s the WordPress issue ticket: https://core.trac.wordpress.org/ticket/52790. If you’ve experienced this problem, please share as much detail as possible on this ticket.

You can see all your Reusable Blocks here: https://yourdomain.com/wp-admin/edit.php?post_type=wp_block. (Add your domain to the URL.)

Recommendations:

• If you’re on WordPress <5.7 and use Reusable Blocks, don’t update WordPress core at this time.
• If you don’t use Reusable Blocks or are already on WordPress 5.7 or later, you can update to the latest version of WordPress core.

Note that in WordPress 5.8, there were some interface changes that may make editing Reusable Blocks a bit more confusing. We recommend not editing Reusable Blocks while editing a post and instead use the link above to edit the blocks individually.