==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.6.1 MARIADB edition
- Deployed with iRedMail Easy or the downloadable installer?
- Linux/BSD distribution name and version: Ubuntu 18.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL(MariaDB)
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Attempted to change password on roundcubemail's "[My Domain]/mail/?_task=settings&_action=plugin.password-save" page. But I get an error message saying "Could not save new password Encryption function missing."

I checked my mailserver with the solution listed in this forum. However, the workaround has already been applied.

My config.inc.php file is set as below.
$config['password_dovecotpw'] = "/usr/bin/doveadm pw";

And when i enter the command as below, it is normally encrypted and output.
# /usr/bin/doveadm pw -p "this is Deno"
{CRYPT}$2y$05$F0zoP9kObPMu0iE1l9hUTe.PkzRgsKO0k/9OIG07jocdGI47S7vvG

What's the problem?