ISPConfig3 stopped working after server upgrade

After performing the upgrade from Ubuntu 18.04 to 20.04, ISPConfig3 stopped working. At first I had a problem with a LE certificate, for which I temporarily disabled the vhost to at least get into the ISPConfig3 admin interface.
I then tried to update ispconfig using ispconfig_update.sh to get to the most recent version (3.2.4).

I'm stuck with this error message from the log, when I load the admin page in a browser:

Code:

[Tue May 11 16:44:15.071471 2021] [fcgid:warn] [pid 5103] [client 10.0.0.184:39282] mod_fcgid: stderr: PHP Fatal error:  Uncaught Error: Call to undefined function mysqli_init() in /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php:83
[Tue May 11 16:44:15.071505 2021] [fcgid:warn] [pid 5103] [client 10.0.0.184:39282] mod_fcgid: stderr: Stack trace:
[Tue May 11 16:44:15.071508 2021] [fcgid:warn] [pid 5103] [client 10.0.0.184:39282] mod_fcgid: stderr: #0 /usr/local/ispconfig/interface/lib/app.inc.php(66): db->__construct()
[Tue May 11 16:44:15.071510 2021] [fcgid:warn] [pid 5103] [client 10.0.0.184:39282] mod_fcgid: stderr: #1 /usr/local/ispconfig/interface/lib/app.inc.php(392): app->__construct()
[Tue May 11 16:44:15.071512 2021] [fcgid:warn] [pid 5103] [client 10.0.0.184:39282] mod_fcgid: stderr: #2 /usr/local/ispconfig/interface/web/index.php(32): require_once('/usr/local/ispc...')
[Tue May 11 16:44:15.071514 2021] [fcgid:warn] [pid 5103] [client 10.0.0.184:39282] mod_fcgid: stderr: #3 {main}
[Tue May 11 16:44:15.071516 2021] [fcgid:warn] [pid 5103] [client 10.0.0.184:39282] mod_fcgid: stderr:   thrown in /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php on line 83
[Tue May 11 16:57:40.979944 2021] [fcgid:warn] [pid 5465] [client 10.0.0.184:46350] mod_fcgid: stderr: PHP Fatal error:  Uncaught Error: Call to undefined function mysqli_init() in /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php:83
[Tue May 11 16:57:40.979975 2021] [fcgid:warn] [pid 5465] [client 10.0.0.184:46350] mod_fcgid: stderr: Stack trace:
[Tue May 11 16:57:40.979982 2021] [fcgid:warn] [pid 5465] [client 10.0.0.184:46350] mod_fcgid: stderr: #0 /usr/local/ispconfig/interface/lib/app.inc.php(66): db->__construct()
[Tue May 11 16:57:40.979986 2021] [fcgid:warn] [pid 5465] [client 10.0.0.184:46350] mod_fcgid: stderr: #1 /usr/local/ispconfig/interface/lib/app.inc.php(392): app->__construct()
[Tue May 11 16:57:40.979989 2021] [fcgid:warn] [pid 5465] [client 10.0.0.184:46350] mod_fcgid: stderr: #2 /usr/local/ispconfig/interface/web/index.php(32): require_once('/usr/local/ispc...')
[Tue May 11 16:57:40.979993 2021] [fcgid:warn] [pid 5465] [client 10.0.0.184:46350] mod_fcgid: stderr: #3 {main}
[Tue May 11 16:57:40.979997 2021] [fcgid:warn] [pid 5465] [client 10.0.0.184:46350] mod_fcgid: stderr:   thrown in /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php on line 83

From what I can tell, I do have the proper PHP module enabled that provides the mysqli_init() function (which apparently was the solution for another user with a similar problem). So I'm not sure how else to debug this problem and would highly appreciate some help.

EDIT: Here is some more information
Output of the test script:

Code:

##### SERVER #####
IP-address (as per hostname): ***.***.***.***
[WARN] could not determine server's ip address by ifconfig
[INFO] OS version is Ubuntu 20.04.2 LTS
 
[INFO] uptime:  17:59:50 up  1:26,  1 user,  load average: 0.08, 0.03, 0.01
 
[INFO] memory:
              total        used        free      shared  buff/cache   available
Mem:          7.7Gi       1.8Gi       4.5Gi        17Mi       1.5Gi       5.7Gi
Swap:           9Gi          0B         9Gi
 
[INFO] ISPConfig is installed.

##### ISPCONFIG #####
ISPConfig version is 3.2.4


##### VERSION CHECK #####

[INFO] php (cli) version is 7.4.3
[INFO] php-cgi (used for cgi php in default vhost!) is version 7.2.24

##### PORT CHECK #####


##### MAIL SERVER CHECK #####


##### RUNNING SERVER PROCESSES #####

[INFO] I found the following web server(s):
    Apache 2 (PID 5100)
[INFO] I found the following mail server(s):
    Postfix (PID 1322)
[INFO] I found the following pop3 server(s):
    Dovecot (PID 703)
[INFO] I found the following imap server(s):
    Dovecot (PID 703)
[INFO] I found the following ftp server(s):
    PureFTP (PID 1481)

##### LISTENING PORTS #####
(only        ()
Local        (Address)
[anywhere]:993        (703/dovecot)
[anywhere]:995        (703/dovecot)
[localhost]:10023        (1176/postgrey)
[localhost]:10024        (1426/amavisd-new)
[localhost]:10025        (1322/master)
[localhost]:10026        (1426/amavisd-new)
[localhost]:10027        (1322/master)
[anywhere]:587        (1322/master)
[localhost]:11211        (718/memcached)
[anywhere]:110        (703/dovecot)
[anywhere]:143        (703/dovecot)
[anywhere]:465        (1322/master)
[anywhere]:4242        (730/quasselcore)
[anywhere]:21        (1481/pure-ftpd)
***.***.***.***:53        (721/named)
***.***.***.***:53        (721/named)
[localhost]:53        (721/named)
***.***.***.***:53        (684/systemd-resolve)
[anywhere]:22        (949/sshd:)
[anywhere]:25        (1322/master)
[localhost]:953        (721/named)
*:*:*:*::*:993        (703/dovecot)
*:*:*:*::*:995        (703/dovecot)
*:*:*:*::*:10023        (1176/postgrey)
*:*:*:*::*:10024        (1426/amavisd-new)
*:*:*:*::*:10026        (1426/amavisd-new)
*:*:*:*::*:3306        (997/mysqld)
*:*:*:*::*:587        (1322/master)
[localhost]10        (703/dovecot)
[localhost]43        (703/dovecot)
*:*:*:*::*:8080        (5100/apache2)
*:*:*:*::*:80        (5100/apache2)
*:*:*:*::*:8081        (5100/apache2)
*:*:*:*::*:465        (1322/master)
*:*:*:*::*:4242        (730/quasselcore)
*:*:*:*::*:21        (1481/pure-ftpd)
*:*:*:*::*8c5c:34ff:fe87:53        (721/named)
*:*:*:*::*4c97:3fff:feec:53        (721/named)
*:*:*:*::*:53        (721/named)
*:*:*:*::*:22        (949/sshd:)
*:*:*:*::*:25        (1322/master)
*:*:*:*::*:953        (721/named)
*:*:*:*::*:443        (5100/apache2)




##### IPTABLES #####
Chain INPUT (policy ACCEPT)
target     prot opt source               destination        
f2b-sshd   tcp  --  [anywhere]/0            [anywhere]/0            multiport dports 22

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination        

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination        

Chain f2b-sshd (1 references)
target     prot opt source               destination        
REJECT     all  --  ***.***.***.***       [anywhere]/0            reject-with icmp-port-unreachable
REJECT     all  --  ***.***.***.***          [anywhere]/0            reject-with icmp-port-unreachable
REJECT     all  --  ***.***.***.***        [anywhere]/0            reject-with icmp-port-unreachable
REJECT     all  --  ***.***.***.***       [anywhere]/0            reject-with icmp-port-unreachable
REJECT     all  --  ***.***.***.***       [anywhere]/0            reject-with icmp-port-unreachable
REJECT     all  --  ***.***.***.***        [anywhere]/0            reject-with icmp-port-unreachable
REJECT     all  --  ***.***.***.***        [anywhere]/0            reject-with icmp-port-unreachable
RETURN     all  --  [anywhere]/0            [anywhere]/0          




##### LET'S ENCRYPT #####
Certbot is installed in /usr/bin/letsencrypt

Output of lsb_release -a

Code:

No LSB modules are available.
Distributor ID:   Ubuntu
Description:   Ubuntu 20.04.2 LTS
Release:   20.04
Codename:   focal

Output of php -v

Code:

PHP 7.4.3 (cli) (built: Oct  6 2020 15:47:56) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with Zend OPcache v7.4.3, Copyright (c), by Zend Technologies

I'm using Apache2 (which ofc is evident in the output of the test script)

 

Thank you for pointing me at that thread. I extended the information, hopefully to satisfy the requirements to post. I hope the output helps to identify my problem, for which I didn't find a solution in the FAQ.

 

That makes me suspect you have not after upgrading to Ubuntu 20.04 followed the ISPCOnfig Perfect Server Guide for Ubuntu 20.04. You need to install all the packages and do configurations.
Then force reconfigure services in ISPConfig using

Code:

ispconfig_update.sh --force

This is suspicious:

Code:

[INFO] php (cli) version is 7.4.3
[INFO] php-cgi (used for cgi php in default vhost!) is version 7.2.24

Why are those different versions?

 

I indeed did not follow that guide after the upgrade, thank you for pointing that step out. I did install every package mentioned in that guide and ran the configuration as indicated.
This did the trick. Thanks for extremely quick and great help