Swyh --> HEOS1 not working

I am running swyh v1.5.0+27e8167 on Windows 10 Pro 64 and trying to stream to a HEOS1 HS2.

I can select the HEOS1 in swyh, and in the Android controller select Music Servers, swyh, music, and either the mp3 or the PCM/L16 streams.

Irrespective of which setting I use get this message: an unknown error occurred. error code-23

Does anyone know what this means?

Does anyone have a suggestion to fix it?

Thanks.