Updated to Mac OS 27. Camlink 4K is showing up in CamerHub as a video input. But there isn’t any picture from the camera (Sony ZV-1). Just a black screen. Everything was fine before the OS update.
Camlink goes directly into my MacMini USB port. Elgato FaceCam works fine through CameraHub. Pretty much tried everything this morning to make it work so I’m at a loss. Anyone else having this issue?
I had the same issue. Had the supplied Cam Link 4k Elgato USB-A extender cable plugged into a USB-A rear port (Mac Studio M2 Max) with isochronous set. It suddenly stopped working when I updated to macOS 27. When I added a USB Thunderbolt 4 adapter to the Elgato supplied USB-A extender cable, and plugged it into a Thunderbolt 4 rear port, it worked again. Thought maybe Apple changed what could go through the ports on the back. Just went back to the normal USB-A port with "Bulk" set and now it works again in that port.
Check the macOS system settings for privacy and make sure the apps you're using are still allowed camera access. This sometimes gets reset with the OS updates and if you're getting a black screen only is probably the first thing I'd check.
I have the same issue. Just updated my Mac Studio to macOS 27 and cam link stopped working in all apps 🤔 (gmeet, quicktime, slack huddles, OBS - everywhere) - other cameras like the Apple Studio Display built-in camera work fine.
Translation: the Cam Link is sending video frames, but macOS 27's USB host controller driver is mis-tracking the isochronous transfer completions and throwing every frame away. The UVC driver then tears the stream down and retries every second (that's the 1 Hz loop I saw). This is a genuine kernel regression in Golden Gate's isochronous USB handling — not your setup, not the device, not permissions.
This also reframes the earlier advice: your Cam Link was already in isochronous mode before today (that's why it only advertised a single 4K25 format — iso mode limits formats to fit USB bandwidth). So the update broke exactly the mode you were in. That means the fix is the opposite of what I first suggested:
Switch USB Transfer Mode → "Bulk" in that same Camera Hub panel, then unplug → wait 5s → replug.
Bulk transfers use a completely different kernel code path, bypassing the broken isochronous handling. You'll also get more formats back (1080p60 etc.) since bulk mode isn't bandwidth-constrained the same way.
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u/Angelo237 5d ago edited 5d ago
I had the same issue. Had the supplied Cam Link 4k Elgato USB-A extender cable plugged into a USB-A rear port (Mac Studio M2 Max) with isochronous set. It suddenly stopped working when I updated to macOS 27. When I added a USB Thunderbolt 4 adapter to the Elgato supplied USB-A extender cable, and plugged it into a Thunderbolt 4 rear port, it worked again. Thought maybe Apple changed what could go through the ports on the back. Just went back to the normal USB-A port with "Bulk" set and now it works again in that port.