Created a different setup that don't hit the memory issue and it all work. Found my problem ... hidden in the output.
>> BTW, I had a saved preset that I'd transferred from my usual machine to the one I was using for this test. That preset had audio configured to use Fraunhofer but the new machine didn't have the DLL. In the audio settings panel it said I was using regular FFmpeg AAC (no Fran listed) but then I noticed libfdk-aac in the summary panel. End result it that it errored out.