SQL Server Management Studio 18.4 does not install on Windows 2019 RTM (+ SQL2019 RTM )
we get this errormessage when we try to install SSMS 18.4 onto Windows 2019 rtm.
Win10OrWS2016NotSupported = This version of Windows 10 or Windows Server 2016 is not supported. Please upgrade to version 1607 or greater.
Turns out, the OS needed to reboot in order to get SSMS 18.4 installed.