1) If running Morningstar 3.11 firmware (maybe earlier too?), try sending a clock ‘start’ message from the MC6.

2) If running the new Morningstar 3.12 firmware, try:

a) de-selecting any one of the MIDI clock port settings (new feature in General Config),

b) save & restart MC6,

c) change that setting back again (if you don’t want/need to change it back, see step ‘e’),

d) save & re-start MC6,

e) try sending the clock ‘start’ message again.  If still no go, reboot H90, then send the clock ‘start’ message again.