Can vmix run with a newer version of windows desktop runtime installed, such as 6.0.15?
Thanks

I've never had Windows refuse to install an older version of DOTNET, I suspect the source of that article of having messed up their testing that led to them making that claim far more than I suspect vMix can't install the required version of DOTNET.

Specifically, they may have already installed a version of DOTNET and had it updated to the current patch version of that version of the framework and then tried to install an older patch level of that same version of the framework instead of using the built-in rollback to revert to the patch level. Then they misunderstood what they had done and made an erroneous claim is my suspicion.

Refusing to install an older patch level of a version of the framework when a later patch level is already installed is an appropriate action. MS is regularly updating current and older versions of the DOTNET framework as issues with those are found, especially security issues.