HowTo Upgrade to roundcube v1.6.4 on centos 7 ispconfig

perfect, thank you.

 

Solved - thank you for all your help!

What I did to upgrade to RoundCube v1.6.4 from v1.3.9 on CentOS 7.9.2009 with Perfect Server and ispconfig v3.2.9p1:
#First had to upgrade PHP from .5.6 to 7.4.
#But didn't need "epel-release" and "yum-utils" because had already installed on my server:
# yum install epel-release
# yum install http://rpms.remirepo.net/enterprise/remi-release-7.rpm
# yum install yum-utils -y

#Change to PHP7.4 default:
$ yum-config-manager --enable remi-php74
$ yum update -y

#Add "[mysql]" section in "my.conf" config because of old MariaDB:
$ vim /etc/my.cnf
[mysqld]
innodb_large_prefix=1
innodb_file_per_table=1
innodb_file_format=Barracuda

#Get roundcube sources and install:
$ cd /tmp
$ wget https://github.com/roundcube/roundc...oad/1.6.4/roundcubemail-1.6.4-complete.tar.gz
$ tar xfz roundcubemail-1.6.4-complete.tar.gz
$ cd /tmp/roundcubemail-1.6.4/
$ ./bin/installto.sh /usr/share/roundcubemail/

#Answer both questions with "yes":
Upgrading from 1.3.9. Do you want to continue? (y/N)y
Running update script at target...
WARNING: Replaced config options:
(These config options have been replaced or renamed)
- 'default_host' was replaced by 'imap_host'
Do you want me to fix your local configuration? (y/N) y

#Reboot:
$ reboot

#And finally in my case change SMTP port in roundcube config to "25":
$ vim /usr/share/roundcubemail/config/defaults.inc.php
$config['smtp_host'] = 'localhost:25';