I could render and output DVD from QT DNx Avid reference, but a BD output would fail to render and return the Error code stated.
Turns out Matrox Codecs installed with Lightworks was interfering with BD render. Uninstalled the Matrox Codecs and problem fixed.
If you are editing your video first, it is better to render the audio and video from it to formats that suit your BD or DVD, so that DVDA does not have to render anything.
Thanks, been editing for many years. This particular work I had edited in Avid Media Composer, mixed down as DNxHD-145 then exported as a QT reference. AvidDVD does not encode BD as VC-1 (Mpeg2 only)so I used DVD-A.