Thanks David you're onto it. I read all those posts you suggested and this one below solved it. Clicking the Solo button in the Transport did work but you had to do it every time you moved a region. Comment below fixed it. I thought it had to be something simple. I had the same problem in Logic 7 every time I bounced or froze tracks. Thank goodness for that this project is too big to copy over to other projects. Thanks for all your help David and Triplets we need you in NZ. I need to do your course and get trained up so I can represent you here.
Recently came across this MIDI going silent on a region/channel bug?, with an ESX24 instrument, using MIDI alt-copied from an External MIDI track.
My fix, which seems to work every time, is to do the following:
(1) Set Track Mute/Solo from Fast to CPU-saving (Slow Response) in Preferences > Audio > General
(2) Click the Transport Solo Button (not track solo) twice to switch Solo mode on, and off again.
(3) Set Track Mute/Solo back to Fast
Doesn't seem to matter if the offending track and/or it's regions are selected.
Logic Pro 9.1.8 (1700.67) (32-bit) - running on Mac Mini Server 2.0 GHz (i7-2635QM), OS X Lion 10.7.5
(Prism Orpheus (clock master) + RME Fireface UCX + Behringer ADA8000) <-> RME Digiface