Thank you for your quick feedback 
I am not sure to understand what you are asking me
Thank you too for keeping/making YNH and its app affordable for non-sysadmin :).
See the file /var/www/flarum/config.php
Error message:
Before the YNH and Flarum update, it was working :).
Thank you for YNH and Flarum.
Amicalement, José