M4 not recognised by Mac after switching off and on

[csansom]

Has anyone else encountered this? If I switch my new M4 off then on again I have to restart the Mac before it'll 'see' it - and even then it may be unresponsive and require another restart. Like others here my Mac stays on and awake (not the display) 24/7, but it seems a bit wasteful to leave peripherals like the M4 on when they're not needed, especially overnight, but it seems I have to if I don't want to have to keep restarting.

[mikehalloran]

It’s bus powered. Most such devices will eventually show up again if turned off and on but it may take a few minutes.

You installed the MOTU drivers, yes? The Mac may need to be restarted if using 3rd party drivers to reload them.

If you were using Core Audio only, this shouldn’t be an issue — and isn’t with mine.

This should be an issue only with portables to save a bit of battery life. No reason to turn off a bus powered interface on a desktop Mac.

[csansom]

Thanks, Mike - and apologies for not noticing your reply until now. Yes, the MOTU driver's installed, and it's not a battery powered Mac.

I've been carrying on a fairly extensive correspondence with Travis Hagan at MOTU support, but we haven’t cracked it yet, and it's now got more serious - I'm getting nothing out of it at all. At Travis's suggestion I tried it on another Mac (my previous iMac, which my wife now uses) and it behaved impeccably. I switched it off and on again: came straight back. Un- and replugged it: same result. I wondered if maybe the driver might be an issue, so I downloaded and installed it on her Mac and repeated the test: all fine. This at least reassures me that the M4 itself is almost certainly OK.

An oddity is that in my Sound menu (and the Sound pref pane and Audio MIDI Setup) I have not one but two entries called 'USB audio CODEC', one of which has both output and input volume sliders in the Sound pref pane, the other output only. Rather to my surprise Travis seems not to know anything about this, but might one or both of these be creating a conflict of some sort? He suggested I look in my /Library/Extensions folder for anything suspicious, and I removed several ancient .kext files that relate to old hardware I no longer use (such as a Wacom tablet), but that made no difference.

Now, every time I restart, the M4 is there in the menu etc., but totally unresponsive.

Any further clues would be greatly appreciated!

[CharlzS]

An oddity is that in my Sound menu (and the Sound pref pane and Audio MIDI Setup) I have not one but two entries called 'USB audio CODEC', one of which has both output and input volume sliders in the Sound pref pane, the other output only.

Do you have some type of dock/expansion along with the M4. When I was using a CalDigit dock with my Mac that type of USB codec I/O would show up.

[Andy Diamond]

Hi there, I have been having this problem constantly since owning my M4.

Very frustrating since the unit itself is great.

I am using Mac Book Pro late 2016/2.9/16GB/2TB on OS 10.14.6.
I use Logic X.

When I plug in the M4 the MBP sees it - as in it shows up in the Sound preferences as M4 but often the signal does not get routed to it (the sound just comes out of the MBP speakers).
Switching the unit on and off and/or unplugging it does not do anything.

I am using a USB cable with the Type C connector at both ends.

I also use Sonarworks Reference 4 which outputs to the M4 also, but that cannot 'see' the M4 all the time either.

I have to quit all my apps and restart the Mac to get the M4 to work but even doing that doesn't guarantee it gets recognized.

I have wasted a lot of time trying to get it to be recognized - very annoying.

PS: all drivers for the MOTU and Sonorworks are up to date.

[mikehalloran]

Try with Core audio. Only the foldback options are disabled. Remove the MOTU drivers and see if this changes anything.

[Andy Diamond]

OK will try that!

[Andy Diamond]

Try with Core audio. Only the foldback options are disabled. Remove the MOTU drivers and see if this changes anything.

I can't seem to find any MOTU or M4 drivers in my system.
There is no uninstall app either.
Any ideas?

[Andy Diamond]

actually I found it in the Library folder - Spotlight wasn't finding it originally.
Have removed it and testing to see what happens.

[csansom]

Well, to my amazement, having switched it off last night as it wasn't working anyway, I just switched it on on the offchance and... not only did the Mac recognise it straight away, but it works!

So in view of that I'll leave well alone for now. But Andy, which Library folder did you find the driver in, and what's the file called? I can see no sign of it in either /Library or ~/Library, nor can I see a MOTU folder (or anything related) that it might be in.

[Andy Diamond]

But Andy, which Library folder did you find the driver in, and what's the file called? I can see no sign of it in either /Library or ~/Library, nor can I see a MOTU folder (or anything related) that it might be in.

Go to the Finder menu > Go > Computer > Mac HD (or whatever your computer is called) > double-click your Mac HD icon > Library > Extensions
Then look for MOTUCoreUAC.kext and delete it.

Hope that helps.

So far it seems to be working for me but I will update later.

[csansom]

Thanks, yes, there it is! I could swear I looked earlier and didn’t find anything MOTU*. However, as it all seems to be working for me at the moment I'll leave that where it is. Definitely borne in mind for later though.

[Andy Diamond]

No probs - yeah weirdly Spotlight did not find that either so...

I am not using the loopback function myself so it's no biggie to delete it in the interim.

[mabbels]

Hey there!

Just stumbled upon this thread & I´m not sure if this is the same issue I´ve described in another thread. Really bothers me a lot atm.
I just deleted the file within the "extensions" folder, but I still have no sound through my (regcognized) M2. The only solution will again be to restart my Mac.

Was this a permanent solution for you?

[csansom]

I haven't trashed the driver file (yet?) and the M4 is still working properly, but I haven't switched it off or disconnected it for a couple of days. So I don't know if anything's a permanent solution yet - I'm just not tempting fate.