Hi I test on a test machine the OTRS upgrade from 2.2.6 to 2.3.1: 1) I have do a clone machine with otrs as the real machine (OTRS 2.2.6) 2) I have upgraded as explain in the UPGRADING file * install the new release 2.3.1 * i have copied the Kernel/Config.pm and GenericAgent.pm * I have upgrade with DBUpdate-to-2.3.mysql.sql (no error) * I have run DBUpdate-to-2.3.pl (no error) * I have upgrade with DBUpdate-to-2.3-post.mysql.sql (no error) When I connect to /otrs/index.pl as agent, everything is ok, all work When a customer connect (/otrs/customer.pl , he have a error message and he cannot connect: No MainObject! at /var/www/otrs-231/bin/cgi-bin/../../Kernel/System/AuthSession.pm line 83. The line 83 is: # check needed objects for (qw(LogObject ConfigObject TimeObject DBObject MainObject)) { $Self->{$_} = $Param{$_} || die "No $_!"; <<<< line 83 } The customer backend is LDAP. All is ok and work on the real machine in 2.2.6 since many months. can you help me ? I have the same Config.pm than in 2.2.6 . thank you, Serge