What must remain in the file name of the MSI for it to install correctly?

The requirement for the file name of the MSI to include the term "installkey" is linked to how Windows Installer packages are designed to function. The term "installkey" typically refers to a unique identifier that the installation process uses to recognize and validate the package being installed. This identifier helps ensure that the correct version of the application is being installed and that it is properly associated with the system's registry and other components.

When the installation file is named with "installkey," it facilitates consistent tracking and handling of installations across systems. This is particularly important in environments where multiple versions of software may be present or when certain software dependencies need to be managed.

In contrast, the other terms listed do not hold the same fundamental significance for the installation process. While "MSIversion," "applicationID," and "installTrigger" might be relevant in specific contexts (such as version management or application identification), they do not represent a required element in the MSI file name for the installation to proceed correctly. Therefore, retaining "installkey" in the file name is crucial for ensuring successful installation and proper functionality of the application.