Applies to Launchpad X
To set the Launchpad X up with Ableton Live 10 (minimum 10.1.3), please connect your Launchpad and then open Ableton.
Then go to the Preferences (Options > Preferences on Windows, Ableton Live > Preferences on macOS) and go to the Link/MIDI tab:
Then select the Launchpad X Control Surface:
And then set the Launchpad X DAW Out and DAW In for the Input and Output ports:
Then have the MIDI port setup match the settings shown below: