Thank you, you are correct. I updated from 2.4 to 3.2.4. I rolled back the upgrade, now everything works again.
Is there a way to update an old version without breaking the elements?
Any update on this? Version 3.2.4 does not fix the problem! All wrapper blocks still say “This block contains unexpected or invalid content.” My whole website is broken because Gutenberg doesn’t understand “wp-block-essential-blocks-wrapper”.
