ACT and the MackieControl control surface are different beasts. You can't use them at the same time. You need to make sure that the MackieControl plugin has exclusive control of the Mackie MIDI ports. ACT can't be using them at the same time. To setup, add it as the following (obviously with your own Mackie MIDI Input/Output ports): You should then see it here: Once applied, you should see it under the Utilities menu: Also make sure these options are