[SOLVED] - Stupid rookie error 
I'm new to JUCE (very nice BTW) and wrote a quick-and-dirty test harness to exercise the MIDI I/O with SysEx messages. Well, the messages are valid and sent correctly, they go through the USB/MIDI interface and arrive at the 5-pin din. But the MIDI device on the other end ignores them!?? I can send the same messages with a Java program and they arrive and are accepted by the MIDI device.
I have 3 different USB/MIDI cables that all work perfectly with Windows, Mac and Linux. The Windows and Linux interfaces work flawlessly sending SysEx messages with an app that I wrote in Java. Doesn't work on Mac. So I decided to write a small JUCE app to replace the MIDI I/O of my Java app. I could see the messages being sent off the Mac, through the 3 USB/MIDI interfaces but my receiving MIDI device (a Fractal Audio Systems MFC-101) ignored the messages. So I moved the app to Linux with the very same results. One of my USB/MIDI cables has LEDs in the 5-pin din connectors so I can see the messages arrive at the MFC-101, which ignores them as if there were invalid messages.
I set up MIDI-OX as the receiving MIDI device and connected my JUCE app to that an monitored the SysEx messages and they are byte-for-byte correct and exactly what my little program sent (with sendMessageNow()). So with all humility I'm asking for help or suggestions.
There must be something I don't know, or haven't read yet, about JUCE and sending SysEx messages. One other thing, the first message minus the SOX and EOX is only 6 bytes. The second is 20 bytes long and the longest message is 164 bytes.
Can anybody help?
Thanks!
P.S. Congratulations on the acquisition and partnership with ROLI Jules!