If available, please run ISScript.msi, or contact your support personnel for further assistance.
If you are installing the TAM ESSO agent and encounter this message, then it is likely that you are using an older version of ISScript.msi than is required.
I ran into this problem recently and spent a few hours trying to install various versions of ISScript.msi. There is an informative tech note from InstallShield here:
The problem is that if you try to install any or all of the versions mentioned in the technote you will still get the error message because InstallShield is already up to like version 12 or there abouts.
You can debug your msi by running this from the command line:
msiexec /i yourmsi.msi /l*v C:\Temp\MyMSILog.log
In the log you will see which version of isscript.msi it's trying to use. That would be the version you must install.
Since I'm using TAM ESSO 6.004 it is requiring version 11.5 of isscript.msi. I found the correct version of isscript.msi bundled with the TAM ESSO 6.004 product. You will find it in the Utility folder. The file name is isscript1150.msi.