Problem to load Midi Bass in logic pro X

but how i can record a track in logic pro with standalone ?

start standalone, open interface section, choose “virtual midi” for midi output.
Run Logic side by side and it will hear the midi autmotically.

MacOS 10.15 Catalina Beta is unstable for almost audio applications strangely including Logic Pro X and Mainstage 3 at this time. Trying to load an Audio Unit in either will result in big problems. Go back to Mojave if you can. Betas are called betas for a reason.

Allthough it is ofcourse not our fault when apple shifts stuff, our users have to live with the consequences. The purpose of these macos beta’s is also to warn developers for breaking changes…
So we take this seriously.