RT::Handle.pm problem

I am installing a fresh version of RT on a redhat 7.3 box. I have
configured and installed RT and have loaded the initial database. I
have configured the web interface as suche:

Request Tracker server (rt.my.domain)

ServerAdmin webmaster@my.domain DocumentRoot /usr/local/rt3/share/html ServerName rt.my.domain AddDefaultCharset UTF-8 PerlModule Apache::DBI PerlRequire /usr/local/rt3/bin/webmux.pl SetHandler perl-script PerlHandler RT::Mason

When trying to access the web interface I get an Internal Server Error
and this error in the logs:

Can’t locate object method “new” via package “RT::Handle” at
/usr/local/rt3/lib/RT.pm line 122

I looked at the FAQ and it says that it probably is because my Database
variable is set wrong. I am using mysql and this is the entry in

Set($DatabaseType , ‘mysql’);

All the permission are correct. From the code in RT.pm it seems that a
subroutine named “new” should be in Handle.pm. There is no such subroutine
in /usr/local/rt3/lib/RT/Handle.pm. I am not a coder so my logic might
be flawed.

Does anybody have any ideas? Thank you for your time.