Unable to upgrade the software image to version 7.x on ASA 5520
To upgrade the software, perform these steps:
Refer to the Upgrading to a New Software Version section of the Release Notes for more information
Note: A new SSL VPN License will be required for running the new software version, starting with version 7.1.x. The license can be obtained from firstname.lastname@example.org by sending a show version of the system after the upgrade has been done.