Upgrading from 2.2.18 to 2.2.24. When ISPConfig restarts at the end of the upgrade, I get this: Shutting down ISPConfig system... /root/ispconfig/httpd/bin/apachectl stop: httpd (no pid file) not running ISPConfig system stopped! Starting ISPConfig system... Syntax error on line 205 of /root/ispconfig/httpd/conf/httpd.conf: Cannot load /root/ispconfig/httpd/libexec/libphp5.so into server: /root/ispconfig/httpd/libexec/libphp5.so: undefined symbol: compress /root/ispconfig/httpd/bin/apachectl startssl: httpd could not be started ISPConfig system is now up and running! ISPConfig won't actually start back up. This is on a CentOS 5.1 system.
There should be a backup of the /root/ispconfig folder in /tmp. You can try to unpack it and copy the libphp5.so from the backup to /root/ispconfig/httpd/libexec/libphp5.so. MAybe this works. Is SELinux disabled?