The installation of the Symantec Endpoint Protection Manager 11 (SEPM) rolls back after reaching "Configuring IIS".
Per the SEPM_INST.log:
Property(C): DialogCaption = InstallShield for Windows Installer
Property(C): DisplayNameCustom = Custom
Property(C): DisplayNameMinimal = Minimal
Property(C): DisplayNameTypical = Typical
Property(C): ErrorDialog = SetupError
Property(C): INSTALLLEVEL = 100
Property(C): ISNEC = 0
Property(C): ISSCRIPT_VERSION_MISSING = The InstallScript engine is missing from this machine. If available, please run ISScript.msi, or contact your support personnel for further assistance.
This error occurs when the InstallShield application is corrupted or is damaged.
Renaming the InstallShield folder has been reported to resolve the issue in most cases.