1) When using a patch that only has a virtual instrument controlling a
third-party plug-in place on a bus (SooperLooper, Augusts Loop)
sometimes stops working. However, if you just add an audio trackt to
the patch it works fine. So this bug does not even affect people that
play acoustic/electric instruments. If you play virtual instruments by
external MIDI the workaround of adding an audio track is a no-brainer
(you can mute its input if not using it).
2) When using a looper plug-in that sends out MIDI Clock that
MainStage syncs after it freezes after a while. This is probably due
to MIDI Clock being virtually passed through MainStage so a MIDI Clock
feedback loops builds up. This bug only affects those who long for the
"first loop setting the tempo" style of looping. Everyone that is fine
with setting the tempo in MainStage, manually or by tempo tapping a
pedal, stays clear.