Site does not include support for uagb/section block

I had created a lot of content with Ultimate Add on and some other Gutenberg addons on my website but now they are coming out as garbled. For Ultimate blocks, I’m getting the following error:
“Your site doesn’t include support for ‘uagb/sectio’ block. You can leave this block intact, convert its content to a custom HTML block, or remove it entirely.”
I’m then given the option of clicking ‘Keep as HTML’ but when I click on it, I’m unable to save it.

I have updated the Ultimate Add on to its latest version.

How do I convert it into a Gutenberg block, doesn’t have to be a uagb block.

The page I need help with: [log in to see the link]