The ticket cannot be renewed. This could be because the ticket was not flagged as renewable when you obtained it, or because it expired before you could renew it, or because the ticket's renewable lifetime has been reached. About: Renewable Tickets
MIT Kerberos can only renew your tickets if the program is running and active. It cannot renew your tickets if you exit the program or if your computer is turned off or in hibernation mode.
Your Kerberos installation is configured for a maximum ticket lifetime length that is determined by the administrators. If your installation uses a shorter maximum ticket lifetime than the default, the Ticket Lifetime slider might show the default maximum instead of the actual maximum.
For example, if your Kerberos installation has been configured to issue tickets that expire in 5 hours or less, you might be able to move the slider to show 12 hours but you would still be issued a ticket with a lifetime of only 5 hours.
You cannot use the MIT Kerberos program to set properties such as default ticket lifetimes. Instead, edit the appropriate configuration file. For more information, visit the MIT Kerberos documentation site.
When you try to use a Keberized application, it requests your credentials from Kerberos. Some applications do this by asking for a specific principal's credentials, but others ask generically. When applications make a generic request, Kerberos does not know which principal is being authenticated and checks the default principal for tickets. If the default principal is not the one being authenticated, the application will usually simply fail to work with no warning or notice. How to: Make Default Principal