I've been pulling my hair out over this one for days. I'm able to access the plug in itself in both Garage band and Logic Pro X, but when I try to open a song or even a style inside of the plug-in, there is no response. Both DAWs seemingly have not scanned the necessary sounds/units. I have the latest build of UltraPak and patches. Tried rescanning the plug-in which scans fine with no errors. Some Apple Support pages discuss deleting an audio cache file but it no longer exists on the latest Catalina update as far as I can tell. I've deleted the BIIB plug-in and put it back in and it always says validated with no errors. I have another MacBook and all is fine there so I can't figure out why it scanned and found all the sounds/styles there but not on the other.

Thank you for the feedback jcnash. I'm sorry for any frustrations you had while using the plugin. So to be clear you are able to use the plugin on one of your Macbook's but not the other? The plugin actually calls on another app that is in your bb folder (where Band-in-a-Box is installed). In the bb folder there is an app called bbm4.app which should get launched when you try to select a style or open a song. I would first check that the app is in the correct location and that it works when you double click on it. If there are any issues or you are unsure you could always try to reinstall the plugin from scratch using our installer. You could also try comparing the files, or even copy/pasting folders from the working Macbook to the not working Macbook. In any case try some of these suggestions and let us know if you are still having issues. Hope this helps!

Adar