… Yes Felipe, strange indeed. Even after checking the Force box the problem persists.
Regarding my machine: MacBook Pro (Mid 2012), 2.6 GHz Intel Core i7).
So quite old, but it works fine with Max 8 and is updated to OM 6.18.
Looking forward to try your v1.1!
Best
Markus
Hi Markus,
Sorry the issue still persists — miniOMsynth-v1.1 is now available on my github, which lets you use OM’s midi-player as well.
As you might know already, the problem with using midi-player in OM is that it’s very limited — the microtones are automatically routed through different MIDI channels (chan1 for 1/2 tones, chan2 for 1/8 tones, and chan3 for 1/4 tones) which means 1) you can’t really use channels as different instruments, and 2) 1/8 tones is the highest resolution you’ll be able to get.
There’s also some re-patching I need to do to optimize miniOMsynth for MIDI playback, but I hope it’s a workable solution for the time being.
Let me know,
FTH
Hi there!
There is one good news: if you get this error, it means that you are set up correctly in OM and your MIDI notes are now indeed routed through OSC over UDP when they are played (instead of using the MIDI player).
The bad news is that the UPD layer apparently doesn’t work and I’m not sure you can do much about it. 
The call:
(comm:get-host-entry "localhost" :fields '(:address))
should resolve “localhost” to an IP address. In your case, probably not, and therefore the connection fails with the error you reported.
ps. If this is just the translation of “localhost” that fails, you can maybe try the following:
(defun note-osc-events (pitch vel dur date chan)
(let ((evt (make-instance 'oscevent
:host "127.0.0.1" :port *osc-score-output*
:bundle (list "/om/note" pitch vel dur chan))))
(setf (offset evt) date)
(list evt)))
this redefines note-osc-events with “127.0.0.1” as hostname, which in principle is equivalent to “localhost”.
Hi Jean
Thanx for your reply. Is it maybe because Markus’ port is not opened for some restricted permission?
Just asking?
Best
k
Yes, probably not the port (it’s about resolving the host). I’m not sure what. 
Sorry yes i meant the host.
@Markus Check your network settings. Did you change your localhost to other than 127.0.0.1 ?
Hi Karim- I didn’t change anything in my localhost settings- I suppose that “Markus-Busers-MacBook-Pro-15.local” means 127.0.0.1. Sorry I am zero in network settings…
Hi Felipe,
Thank you for miniOMsynth! Seems to work flawlessly over OSC. I’m in Mojave/OM6.18. I have mid-2017 MacBook Pro.
Best wishes,
Maija
Good evening,
Thanks to the standalone version of felipetovarhenao’s miniOMSynth, I finally solved the microtonal reading for the Mac under OM7 and under windows 10 with OM17. I had tried Fluid Synth which I had seen in Mikhael Malt’s video tutorial, the interface was functional but there was no way to download the soundfonts as other users have pointed out. obviously this version was not updated for Big Sur. I tested the MiniOMSynth and if under Max 7 or 8 there are problems related to missing objects, the player works with the standalone version under Big Sur and Windows 10.
Best.
Didier