Avatar Editor not coming up

I tried running the Meta Avatar Editor in the example Unity scenes included in the SDK samples (using the OpenAvatarEditor object + script) but it doesn't do anything or display any errors or debug messages at all.  I have the 24.0.1 version installed.  Has anyone encountered this?  Is there some other way to get it working that I'm missing?  The code in the OpenAvatar Editor looks like this (excerpt):

AvatarEditorOptions options = new AvatarEditorOptions();
options.SetSourceOverride("avatar_2_sdk");
var result = new Request<Oculus.Platform.Models.AvatarEditorResult>(Oculus.Platform.CAPI.ovr_Avatar_LaunchAvatarEditor((IntPtr)options));