I made this change "%windir%\system32\WindowsPowerShell\v1.0\powershell.exe" as I'm using the 64 bit version
And in the script I changed "TSProgressUI.exe" to "Explorer.exe" and then it worked
Sourced from: https://smsagent.blog/2016/02/19/prompting-the-end-user-during-configmgr-application-installs/
Hope this helps...after two years