On a different server after php7.2 install - can't access ispconfig panel

on a client server - I add repository ppandrej
and installed debsury php7.2.
installed all extensions like mysql, gd, curl etc.
after that I am not able to access ISPCONFIG Panel.
in the error log I see

Code:

[Tue Feb 09 18:06:54.869095 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: PHP Fatal error:  Uncaught Error: Call to undefined function mb_detect_encoding() in /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php:527
[Tue Feb 09 18:06:54.869234 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: Stack trace:
[Tue Feb 09 18:06:54.869242 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #0 /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php(179): db->escape('interface')
[Tue Feb 09 18:06:54.869260 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #1 /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php(298): db->_build_query_string('SELECT `value` ...', 'interface', 'session_timeout')
[Tue Feb 09 18:06:54.869267 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #2 /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php(337): db->_query('SELECT `value` ...', 'interface', 'session_timeout')
[Tue Feb 09 18:06:54.869272 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #3 /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php(363): db->query('SELECT `value` ...', 'interface', 'session_timeout')
[Tue Feb 09 18:06:54.869278 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #4 /usr/local/ispconfig/interface/lib/app.inc.php(166): db->queryOneRecord('SELECT `value` ...', 'interface', 'session_timeout')
[Tue Feb 09 18:06:54.869283 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #5 /usr/local/ispconfig/interface/lib/app.inc.php(93): app->conf('interface', 'session_timeout')
[Tue Feb 09 18:06:54.869288 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #6 /usr/local/ispconfig/interface/lib/app.inc.php(398): app->initialize_session()
[Tue Feb 09 18:06:54.869293 2021] [fcgid:warn] [pid 15144] [client 49.37.5.140:56564] mod_fcgid: stderr: #7 /usr/local/ispconfig/interface/web/index.php(32): require_once in /usr/local/ispconfig/interface/lib/classes/db_mysql.inc.php on line 527

How I can fix this?
from the only website I installed I can access phpinfo file. which is showing as 7.0.33 and mbstring enabled.

 

Hi! Check if ispconfig has access to its db: dbispconfig

 

don't know Till. but it worked I just installed mbstring again.