If you bought a QlikView EE server license in or before 2012, they should still work if they weren't of the Temporary type.
What won't work is installing the newest QlikView server release with a license for which you haven't paid any maintenance fees for 5 years. If you cancel your maintenance payments, you will only be able to install/upgrade to the last version released in the last maintenance period.
Qlik has a policy for customers that want to pick up maintenance again, after a period of non-payments. If this situation applies to you, contact your partner/account manager to discuss a maintenance renewal and the associated costs.