Answer
If you get the error below when trying to open a .msi package to create a .mst file for deployment, please first make sure you are on the right version of the Customization Wizard tool. For example, if you are using a V11 .msi package, you must make sure that the Customization Wizard is on a V11 install as well.
Secondly, please make sure that the .msi is stored within the C: Drive. The Customization Wizard is not compatible if the .msi is stored in a network shared drive. You can change the install path within the Wizard itself, but the .msi file must be accessed from the local drive.
When deploying the software, please also make sure that all files are within the same location. This will include the .msi, the .mst, and the fct.cab file.