Problem
During the MassCore - Interval Zero RTX64 installation through MT Security panel, the installer rolls back and fails.
Your MassCore / RTX64 license is hosted on a dedicated dongle (SSK-HUD-RTX)
Solution
There is a compatibility issue between the dedicated MassCore / RTX64 license dongle (SSK-HUD-RTX) and the CEDAR license dongle.
Go in Windows Control Panel > Programs & Features and uninstall "Sentinel Runtime" (you may sort the programs by Installation date, to see which one was installed at the same time as "CEDAR for Pyramix64").
Reboot your computer.
Go in MT Security panel > MassCore tab and reinstall MassCore
After the MassCore installation, the CEDAR license dongle will work as well.