Loss of Playback Engine Mid-Session

[DEliker]

Started running into this a week ago.

ProTools is randomly freezing and then failing to see my Clarett 2 interface.
Upon rebooting the app, the input is missing. Only the Aggregate is seen as a playback engine choice.

Yet all other 3rd party apps and internet work, and the System still sees my Clarett and other devices.

Trashing the Preferences, full shut-down and restarting the system, reinstalling PT, doesn't resolve the problem.

Yet the next day or a couple hours later, I'll fire up the system and everything works again. Completely inexplicable. Happened twice today right in the middle of simply playing back a single voice track. The app freezes, then restarts, and the device is lost.

I've gotten this message when first trying to access the Playback Engine:
Could not complete the Playback Engine command because Assertion in "/Users/autobld/gitlabci/PT/release/2021/r2/ProTools/DFW/Views/UMenu.MacOS.mm", line 1843.

Anyone thoughts? It's really getting in the way.
If it was a device issue, the system shouldn't see it and other apps shouldn't work.
If it was a simple crash, the device should be seen upon reboot.
But the app is refusing to see anything else.

Grateful for any help.
Thanks.


Specs:
2018 MacBook Pro
macOS Big Sur 11.4
Clarett 2 Pre USB
ProTools standard 2021.6

[Obsidian Dragon]

My first instinct says to suspect the cable to your interface. The Clarett 2 is USB or USB-C so I'd start to try replacing that cable. That's where I would start.

[DEliker]

Hi Obsidian,

Maayybbeee. But...

That wouldn't explain why the MacBook still sees everything.

Here's the hardware cabling:
Focusright Clarett 2 to Thunderbolt 3 Dock via USB-C.
Thunderbolt 3 via USB-C to the MacBook Pro.
(Also in to the Thunderbolt 3 are Ethernet for Source-Connect, iLok dongle, and Firewire 800 for Glyph external HD)

If it was the cable from the Clarett to the docking station, I'd expect not to see the Clarett recognized by the Mac OS, play audio from other apps, or see it register input on the Focusright Control app. But System Info sees it.

If it was the cable from the Dock to the MacBook, I'd expect neither the Clarett nor the Dock to be seen by the computer. But they are. Just not by Pro Tools.

I'd also expect to not read audio from the external HD. But I can obviously open session folders and play individual audio files directly outside of PT. So data is being sent and read.

[JFreak]

Big Sur has has strange connection issues so first thing I would do is update to latest version and try again. Also, if the problem still persists, some have reported that removing external displays helps, only use one. Sounds like sorcery but something in Big Sur is broken and you just need to wiggle everything to find out what works.

[Obsidian Dragon]

I would test by simplifying the variables. Try Protools with just the power adapter and a USB-C to USB-Clarett cable (I'm not sure if the Clarett side is USB-C or USB-B). Don't go through a Thunderbolt hub. Don't have multiple external monitors connected. Don't have external hard drive connected if possible. Have your iLok on a USB-C to USB-A dongle. No Bluetooth devices, external keyboard or mouse. Keep it simple and test. Too many devices fighting for your USB/Thunderbolt ports may cause conflicts or provide insufficient power to some devices. At least test to rule out this condition. Again, cables can go bad. Protools may check for the interface's connection more often than the other application or OS.

[originalscottyg]

Originally Posted by DEliker

Hi Obsidian,

Maayybbeee. But...

That wouldn't explain why the MacBook still sees everything.

If the interface drops out for a moment, macOS can re-connect to it once it comes back online, so you don't see it as being offline when you switch over to system settings, as it has already re-connected. Pro Tools will not reconnect to an interface or playback engine if it drops out without relaunching the app.

[DEliker]

Hey thanks, guys. All good suggestions. Think we might have got it, fingers crossed.

Had a support session with Avid last evening and before that, did a little reworking by plugging the Clarett directly into the computer and moving the cable between the OWC Thunderbolt to different ports on both ends. Nothing worked. Flushed the PRAM a couple times, a couple of full shutdowns, same. Thought about updating the OS to 11.5 but didn't want to muddy the waters with that just yet.

Worked with Avid for about 30 minutes on it when everything suddenly reappeared in the Playback Engine options and I was back in action. Still don't know exactly what it was that changed. Can't quite point to cause and effect.

Avid's best guess at the moment is that it might not be cable or port, but rather something internal to the Thunderbolt hub that was being overloaded. So we're going to watch it for the next week and see if the problem manifests itself again with the new wiring config.

The OWC unit was recommended by Sweetwater when I originally set this up. But I suppose it's possible it's just not keeping up any more.

So, I hesitate to call this solved just yet. I'll let you know.

Any replacement suggestions for the hub, I'm open.

Thanks!

[Rich Breen]

Yeah, I'm with Scott - just 'cause the OS appears to reconnect doesn't mean the interface isn't momentarily going offline causing ProTools to throw up.

Of course, no one can say with certainty, but it really does smell like hardware to me - I'd be taking a long look at cabling, hubs, all peripherals.

[DEliker]

I'd could see why the OS may reconnect and appear available while Pro Tools wouldn't without a relaunch. But it doesn't explain why relaunching the app won't see anything but the aggregate I/O.

Points to something else, and yes, I'm suspecting the OWC Thunderbolt 3 dock as everything was running through it. Not sure exactly how to test for it though, to be sure.

Usual playback engines seen are:
PT Playback Normal.jpg

Relaunching after the problem presents produces this:
PT Playback on Relaunch.jpg

Now, if it's the dock, I get why both the interface and the dock might not show upon relaunch. I can't explain the rest missing as they're software/system options. But there you go.

I've been a little suspicious of the Thunderbolt dock after replacing my Mbox 3 Mini with the Clarett, which requires an external power source. Switching the Clarett on, the light on my iLock dongle plugged in the dock would often go out.

[originalscottyg]

I'm currently using an OWC TB3 dock (14-port) on a 2019 MacBook Pro i9 and it's rock solid. But, I'm using an Avid HD Native TB + Omni system, connected to a separate TB bus (other side of the MacBook), and not a USB interface.

Is the Clarett connected via the dock, or directly to the Mac? I would suggest connecting the Clarett to the MacBook Pro directly to the MacBook via a separate bus than the dock, if possible.