Ableton Forum

Nordlead into a Mbox2. Midicables and audio jacks wired.
I get Audio into the channels, but no midi trigger when I press the midi keyboard or play back.
The softsynths work with the "Letter keyboard". but not from the midi keyboard.

NL Midi Out -> Mbox Midi In
Mbox Midi Out -> NL Midi In

Assuming the NL is your Midi keyboard controller, turn local control off, and make sure it's set to receive on Midi Ch 1 for slot A.

In Live's preferences, make sure that Track is enabled for the Mbox's Midi in/out ports.

Create a Midi track in Live, and set its output port to the Mbox on Ch 1.

Choose your favorite patch for Slot A on the NL, and play some notes. If you don't hear anything, turn the NL's local control back on, and make sure it's generating some sound.