UAC Warning complaining about invalid signature while deinstalling

Uninstalling the PowerShell Extensions for Ivanti DSM on a computer running Windows Vista or later with User Account Control activated, results in a warning that an unknown program with an invalid digital signature tries to access the computer.

This warning is triggered by a bug in the Windows Installer, it is not caused by the installer of the PowerShell Extensions for Ivanti DSM. This bug is discussed in the Microsoft knowledgebase article 929467 (