"File is not an actual MSI package of the Host" error

Symptoms

When you try to build a "One-click" or "Agent" package using MSI Configurator, the following alert appears:

File [path_to_file] is not an actual MSI package of the Host.

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Solution

Before you build a "One-click" or "Agent" package, completely uninstall the Host from the computer where you are running the MSI Configurator.