Win Server 2019 (17733) - Adding an optional feature from GUI fails with unhelpful error message

Attempting to add an optional feature in Windows Server 2019 using the GUI. I get to the "Manage optional features" page in Settings and click on 'Add a feature'. It fails with another non-obvious error as shown here:

I can't help but ask: did anyone actually test these kinds of features before this build was released? It seems to me that these kinds of errors just should not happen - the installer really ought to be able to give Enterprise Admin, running on the forest root DC, adequate access to enable simple settings to be updated. And when they do crop up (I know builds can be semi-broken - the joys of pre-release testing), surely the simple things are tested and the build not released if these simple things fail. And where there is either a workaround or a known issue - it should be noted in the release notes. In my environment, this build is just not ready for prime time.