Version 3.9.1 [20/01/2023]

• Resolved an issue introduced in v3.9.0 where toast notifications would not display when run in the system context (#733)
• Added Finnish language translations to the UI components (#681)
• Added variable $IsMultiSessionOS for virtual environments (#697)
• Add missing dash before TypeName parameter used with New-Object in the in Set-ItemPermission function which resulted in failing to set read permissions on the BlockExecution path. (#721)
• Resolved an issue introduced in v3.8.4 where registry entries set by Block-AppExecution would not be cleaned up after an interrupted installation (#714)
• Resolved an issue where a PowerShell prompt would flash on screen when invoking a PowerShell script using Execute-ProcessAsUser (#735)
• Added the appropriate exit code 1638 for MSIs that are already installed when using the Execute-MSI function with -PassThru (#736)
• Added creation of the $dirAppDeployTemp directory by default so the variable can be used for general actions (#708)

Full Changelog: https://github.com/PSAppDeployToolkit/PSAppDeployToolkit/compare/3.9.0...3.9.1