I’ve just got MG3. I can get it to work on Logic Pro X but I cannot get it to work in the standalone app. I can hear my guitar sound coming through, but not midi sounds. I have made sure the audio interface is set to my sound card - Universal Audio Thunderbolt - 256 samples - 44.1 What are the basic steps to get it to work in standalone?

Does the UI react to your playing?

If no, probably you need to enable microphone permission: Mac => Settings => Privacy = > Microphone => MG3

If yes, maybe your interface is set to “direct” or something like that?

Is the MG3 “Logo Guitar” showing light strobes? Did you load any instrument?