Hi there,
I recently went into edit a page on my website and noticed I couldn’t actually edit the fields.
It shows an error message:
Your site doesn’t include support for the “acf/grid” block. You can leave this block intact or remove it entirely.

How would I go about fixing this?
Did you manage to fix this? It has just happened to me too after updating.
I’ve managed to fix it. I included JS in the backend as well and listed ‘acf-blocks’ as a dependency in the enqueue_block_editor_assets
hook. Once that one was deleted it was working fine again.
@levdbas was that in your functions.php file?
Not in my case but it normally goes into a function file yes. You can also try with another browser to login. Sometimes the caching gets in the way.
I’ve tried multiple browsers and it still throws the same error.
In the browser console it’s thowring the following error (screenshot):
Uncaught TypeError: can't access property "BlockControls", C is undefined acf-pro-blocks.min.js:1:9076
I contacted ACF support about this, in turns out upgrading ACF Pro to version 5.9.1 and upgrading WordPress to version 5.5.1 fixed the issue.