I have an older version of IS that the computer it was installed on is no longer accessible so I can't release the license to move it to a new computer. How do I get the license released so that it will activate on the new system?
You will need to contact support. Here's a description how to contact activation chat:
https://community.flexera.com/t5/InstallShield-Knowledge-Base/How-to-Use-Revenera-Support-Chat-to-Help-with-InstallShield/ta-p/133409
