You don't have a synth installed. The MS GS wavetable won't work.

In your Biab install files see the Coyote Wavatable synth and install it. It uses the soundset from your built in MS wavetable but it includes the code necessary for it to work with Biab as a DXi synth. Biab must have a DXi synth. That's what you're missing.

Do you use any other synth for your midi sounds? That Coyote basic synth is pretty weak, few use it for sound but PG put it there so a new user has at least some sound out of the box. They still include the much better Roland VSC but it's old and has not been updated to run on a 64 bit system so it's rapidly fading out for use.

Also, this is for any other new people reading this. You must include all this detail about your computer and config in your original post. Otherwise you're just wasting everybody's time.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.