Errors inside your template. Template will not be saved. Email's templates

Product Support
1

Your software Mautic 4
My PHP version is : 7.4
My MySQL/MariaDB version is (delete as applicable): MySQL/MariaDB version 7.4.22

Updating/Installing Errors.
I am (delete as applicable): Installing / Updating BOTH
installing via (delete as applicable) : Web
*Upgrading via: Command Line

These errors are showing in the installer :

These errors are showing in the Mautic log : Today’s Mautic error log is empty

Your problem
My problem is :

When I save a template even if I don’t modify it pops: Errors inside your template. Template will not be saved.

Steps I have tried to fix the problem :
Open one of the email templates and save it.
Works ok witn Breinz and Blank.

2

There is a solution suggested by @joeyk here: FIX: Errors inside your template. Template will be not saved

Worked for him, but I am still getting error.