[otrs] problems with upgrade from 2.4.7 to 3.0

Hi, I've tried to upgrade my otrs system on a windows server 2008 machine from 2.4.7 version to 3.0.1. Using the youtube video I perform all the steps without problems. I restart my pc but when I tried to authenticate my operator account I obtain this error message: Software: Got no TicketObject! at C:/PROGRA~1/OTRS/OTRS//Kernel/Output/HTML/NavBarModuleAdmin.pm line 29. Another error i receveid when I tried to contact my customer user web page: Software error: Can't use an undefined value as a HASH reference at C:/PROGRA~1/OTRS/OTRS//Kernel/System/CustomerUser.pm line 89. someone can help me? Thanks a lot Alessandro