I have had issue with playing MIDI audio within the Guitar Tutor and after a all day investigating BIAB, this is what I found out:

I have been using ASIO to play all my audio in all my audio programs, with no problem at all... well, lately I have had issues with playing MIDI through The Guitar Tutor window in BIAB. I can play Audio and MIDI normally, but not on the Tutor.

In Order to make it play through the Tutor, I need to copy one of the tracks to the Melody track or the Soloist track, then I can hear it.

Thinking that it could be ASIO related problem, I tried setting the driver to WAS and also to MME.
In doing so, BIAB does not output ANY sound. Not even from the Realtracks.

I can see the metering working and the page scrolling but no sound.
Also tried ASIO4ALL using the laptop own drivers (just to test, as my X-Air drivers do a better job) and had the same results. No sound in BIAB.

So I tried RealBand, and "Master Flatpick Guitar Solos" and these work just fine.

Something must have occurred in BIAB and resetting to default factory settings in the Option menu is not making any difference. I downloaded the (833) build update, again, and re-installed it but unfortunately it hasn't solved the issue.

All drivers in Device manager are up to date and have no other issue with the laptop.

Your help in solving this is appreciated!