Roundcube Internal Error Oops… something went wrong!

I can’t access to webmail.domain.com I get an error for all websites.HestiaCP v1.8.11 is installed. Websites are working on PHP 8.1. How can I solve the problem?

[31-Aug-2023 21:00:28 +0000]: IMAP Error: Login failed for [email protected] against localhost from 196.135.64.43 (X-Forwarded-For: 196.135.64.43). AUTHENTICATE PLAIN: Authentication failed. in /var/lib/roundcube/program/lib/Roundcube/rcube_imap.php on line 211 (POST /?_task=login&_action=login).

I tried this solutions but i get the same error
1-sudo apt-get update sudo apt-get -y install php8.1-mbstring.
2- chown -R hestiamail:hestiamail /etc/roundcube/
find /etc/roundcube/ -type f -iname “*php” -exec chmod 640 {} ;

I hope that you can help me