The script scanning included with VirusScan enterprise modified this registry key
@="C:\\Program Files\\McAfee\\VirusScan Enterprise\\scriptcl.dll"
which caused VBScript to fail. A complete uninstall of VSE 8.7i Repost 4 left this key unmodified, causing VBScipt to fail since this McAfee dll no longer exists. Manually changing the registry key to the windows default:
solved the issue. I am now going to attempt a clean install (not looking forward to verifying steps in KB59996), then uninstall to see if the problem reoccurs, or if this was only caused by the VSE 8.5i - 8.7i Repost 4 upgrade I performed.
For others with the same problem you might attempt the steps in https://kc.mcafee.com/corporate/index?page=content&id=KB52222 , it's possible that unregistering the ScriptCl.dll might fix the registry key. Step 11 in KB50602 How to manually remove VirusScan Enterprise 8.5i also states to unregister this DLL.