the editor is dirty before meta is available

a very simple example would be something like

registerBlockType( 'my/block-name', {
    edit: ( props ) => {
        const { attributes: {myClientId}, clientId, setAttributes } = props;

        useEffect(()=>{
            setAttributes({myClientId:clientId})
        }, [clientId])
    }
})

this would make the editor immediately dirty when the block loads which is not great, but some blocks might have to use that as the clientId is changed on every load of the editor. None the less, TEC will be the good code test for other block devs in it’s current state. I suggested something like this in the subscriber so that this code is not run against posts that are not events.

const postType = wpSelect( 'core/editor' ).getPostTypeLabel();
if( postType!==editor.EVENT ) return;

This only happens when editing a page on /wp-admin/site-editor.php and not /wp-admin/post.php

I also see the same error when adding a paragraph to a page in the site-editor, saving the page, then reloading. After the reload, when I delete the paragraph I get the same error:
Cannot read properties of undefined (reading 'meta')

I observed the error in a new local site with the 2024 theme enabled and no other plugins enabled. In short, the subscriber mentioned in the first comment is too greedy when editing a page with the site-editor