Error Setting Ticket::Type::Default Effective value is not correct

[pvanos]

After installing OTRS 6.0.6 (on CentOS 7.2) and successfully upgrading the database (restored from a 5.0.10 production version), I obtain the following error:
=========================================================
[otrs@lxserver ~]$ bin/otrs.Console.pl Maint::Config::Rebuild
Rebuilding the system configuration...
ERROR: OTRS-otrs.Console.pl-Maint::Config::Rebuild-10 Perl: 5.16.3 OS: linux Time: Wed Apr 11 09:19:28 2018

Message: Setting Ticket::Type::Default Effective value is not correct: Entity value is invalid(Unclassified)!

Traceback (30569):
Module: Kernel::System::SysConfig::ConfigurationDeploy Line: 3465
Module: Kernel::System::Console::Command::Maint::Config::Rebuild::Run Line: 69
Module: (eval) Line: 460
Module: Kernel::System::Console::BaseCommand::Execute Line: 454
Module: Kernel::System::Console::InterfaceConsole::Run Line: 80
Module: bin/otrs.Console.pl Line: 38

Error: There was a problem writing ZZZAAuto.pm.
================================================
The strange thing is that in the http://doc.otrs.com/doc/manual/admin/6. ... icket.html
exactly this value 'Unclassified' is showing for Ticket::Type::Default !
It is also the value present in both the 6.0 and 5.0 versions of /opt/otrs/Kernel/Config/Files/ZZZAAuto.pm
In Sysadmin, for Ticket::Type::Default, I see for current value 'Unclassified' in red Value is not correct! Please consider updating this field.
Other values listed (when clicking this field) are:
default | Change management | Unclassified

So what value am I supposed to fill out here ?
Many thanks

[jojo]

check the entries in the Type administration widget

[pvanos]

In Sysconfig I opened Core --> Ticket::Type::Default and replaced non-accepted value 'Unclassified' by value 'default'.
While selecting, the notification in red "Value is not correct! Please consider updating this field." is not disappearing.
It only does when actually accepting the value by saving it. Maybe a little confusing, but once you know, no prob.

The only thing I wonder is that everyone upgrading to version 6.0 will run into this same problem ?
As the default value for Ticket::Type::Default in version 5 ZZZAAuto.pm happens to be 'Unclassified' ...