Just finally got to the bottom of a rather vexing issue and am posting here for anyone who might be connecting to any of the Eventide stomp boxes (ModFactor, PitchFactor, TimeFactor, Space, H9) via a MOTU MIDI interface and experiencing issues with the H9 Control app.
Apparently the latest MOTU MIDI Installer v1.6.64820 (Release Date 2015-02-10) creates a conflict with Eventide's H9 Control app. I had installed the MOTU updated MIDI Drivers when it was released and last night attempted to use Eventide's H9 Control app with my ModFactor stompbox. It could not establish contact via MIDI with my first gen MicroExpress interface and I'd get a series of error dialogs.
I updated to latest version of H9 Control App… V2.1.0 for Mac 10.10 Yosemite or higher. No go.
I then tried updating to the latest 5.0.0(4) ModFactor firmware via Eventide Direct Updater 1.5.0 (10.10 Yosemite or higher). This was scary. I ran this updater via MIDI instead of USB against my gut instinct. Update froze during the "ERASE…" phase of the update. I had to force quit Direct Updater, power cycle the ModFactor which came up in "UPDATE" mode. I then connected the ModFactor via USB and ran the Direct Updater with no issues and updated the firmware to 5.0.0(4). H9 Control still would not connect to my ModFactor.
FINALLY, I downgraded my MOTU MIDI driver by running the older MOTU MIDI Installer v1.6.4208 (Release Date 2014-10-15), rebooted, and the problem completely disappeared. Anyway… passing this along. I've reported this to MOTU also in case there's a fix on their end.
I don't know if this will affect many people, but posting just in case. I may be an unusual case as I have a MOTU micro express MIDI interface as part of my guitar effects rack which I use to distribute MIDI from my Rocktron MIDI Raider pedal to my effects instead of daisy-chaining them using MIDI Thru.
