Correction! - the midi input is fine and showing up on the monitor - but nothing for output
The little LEDs flash as the Ableton clip is run on the output side. Strange?
Down to me - I changed the USB lead from MidiHub to Computer and now all working as expected. Damn leads, always the last thought!
Further Update - I’ve given up - the issues of either the midi monitor NOT recognizing input and or output continues despite trying different USB ports, different USB leads. Worse - it appears to intermittent, randomly stopping and starting with no real understanding as to why?
So far to day - 5 hours now!
i) I started with it never working.
Then a bit of a break through by switching the filtering on and off - even though it was all set off in the 1st place.
But in practice I have also experienced …
ii) input monitor only working when it should be both
iii) input and output working - good as expected
iv) output only working when it should be both
The only change process going on is making changes via the editor effectively in real time. But even if I laboriously set this up and then run an input / output I still get problems
I decided to re-flash with V 11 - and suddenly Ableton 11 springs into life ie recognizes the unit straight away (this was not the case with V12), all preferences set correctly and simple drag and drop via editor and it works a treat.
Whilst the monitor is useful, it’s not for me the be and end all and I can live without it.
Giedrius, the editor did not ask me anymore to update, so I cannot verify that error message. Maybe something like “Error 7” or “Error -7”. I use Ubuntu 18.04. I did the offline update with the fixed link.
If you’re on Windows, Ableton must be restarted after connecting all the MIDI devices, otherwise it will not be able to use them, or it won’t even list the newly connected ones.
Could you post some screenshots of what output you saw in the MIDI monitor, and what did you expect to see?
When nothing shows up in the monitor, does the activity LEDs on Midihub indicate any activity on the relevant ports? (the LED closest to ‘Midihub’ text reacts to any activity on any of the USB input or output ports)
how do I update the editor when it is running on a raspberry pi?
Just download the new binary, and delete the old one.
where do I find the “binary” for download and where do I find the binary to delete on my RPI?
It’s in the first post, Linux ARM (AppImage)
The ‘Binary’ is synonymous to ‘Executable’ and ‘AppImage’. The AppImages can be placed on your system wherever you like.
Deleting the old version is optional, you may simply run the new one all the time. 
The Appimage is not executable 
(I remember it was the same on 1.11.10)
a wget command would be usefull, since my zero is to weak for working in a browser
You have to do chmod +x to make files/scripts executable in Linux.
wget https://blokas.io/downloads/MidihubEditor-arm_1.12.2.AppImage
chmod +x https://blokas.io/downloads/MidihubEditor-arm_1.12.2.AppImage
./MidihubEditor-arm_1.12.2.AppImage
Thank you for your help. Now I am up to date!