PS> Find-UnitySetupInstaller -Version 2019.1.0b9 2>&1 > error.txt
Could not find archives for Unity version 2019.1.0b9
At C:\Users\jowitt\Documents\WindowsPowerShell\Modules\unitysetup\5.1.111\UnitySetup.psm1:397 char:13
+             throw "Could not find archives for Unity version $Version ...
+             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (Could not find ...sion 2019.1.0b9:String) [], RuntimeException
    + FullyQualifiedErrorId : Could not find archives for Unity version 2019.1.0b9