Database error. If you were saving the newsletter try a table upgrade from…

This week, after updating the AddOn “Extended Composer Blocks” from version 1.3.3 to 1.3.4, and updating WordPress to version 5.8.0, we can no longer create a new newsletter by duplicating the previous one to modify it. We received the error:

Database error. If you were saving the newsletter try a table upgrade from the status panel.

The log shows:

22-07-2021 17:42:57 – FATAL – 7.2.1 – 79.4 MB/512 MB – admin > Got a packet bigger than ‘max_allowed_packet’ bytes
22-07-2021 17:42:57 – FATAL – 7.2.1 – 79.4MB/512MB – admin > INSERT INTO wp_newsletter_emails (subject, message, message_text, send_on, type, editor, track, options)

I tried to disable the add on mentioned, but it didn’t work anymore.