Hi VideoTrack and thank you for your reply, it put my on the right track.

I'm running BiaB 2019 pro package (I bought it yesterday, all this is very new to me) on Windows 10 Home.

I have tested a couple of things in the Pref/Audio to find out that this specific feature doesn't like my Asio driver (Zoom R24). So I changed it to WAS, BiaB was giving me a different error message, but using the 'Get from soundcard' button that run a test solved the issue.

Now the preview feature is working in the standalone version of Biab but he VST is still giving me the "Miscellaneous Error playing" so I guess this is again related to the Asio drivers I am using with in Reaper. The standalone seems to have more features than the VST so that's not a huge issue.

Thanks again!