SB v5.31.4 "The Windows Installer Service Could Not Be Accessed" when trying to install programs.

So I installed v5.31.4 the other day and everything seemed fine, but now though, I'm trying to install Mumble 1.3.0 and I'm getting this "The Windows Installer Service Could Not Be Accessed" error message.

Can anyone else confirm? I don't know if it was from going Beta 5.31.2 to 5.31.4 change that is now showing me this error or if it's a Windows 10 issue... I'm on the latest W10 1903 build also 18362.356.

Here's the download links for Mumble for you guys to try, let me know if you can get the msi installer to work... let me know your OS build version and SB version too would be helpful.

I'd like to know if this works for 5.31.2 but not 5.31.4, or does it not work for both?

Also anyone know where I can download the beta version of SB 5.31.2 in case I need to downgrade to fix this regression?