Hello, I have a CamLink original which worked fine under Debian buster. But then I upgraded to Debian Bullseye. Now I no longer get the vl4 driver for the device. Running a Buster VM on the computer, and then redirecting the USB port inside the VM, this works fine. But ideally would like to get this working without a VM. Any ideas on how to debug this issue? The closest I can see is this bug report: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=966541 - but I don't get any stack trace in my kernel log files. Also this is Camlink, not the newer CamLink 4K. The logs I do get (tail -f /var/log/*.log) after plugging in the device are: ==> /var/log/kern.log <== Aug 24 09:05:13 canidae kernel: [43925.738496] usb 1-1: new high-speed USB device number 12 using xhci_hcd Aug 24 09:05:13 canidae kernel: [43925.889687] usb 1-1: New USB device found, idVendor=534d, idProduct=2109, bcdDevice=21.00 Aug 24 09:05:13 canidae kernel: [43925.889692] usb 1-1: New USB device strings: Mfr=1, Product=0, SerialNumber=0 Aug 24 09:05:13 canidae kernel: [43925.889695] usb 1-1: Manufacturer: MACROSILICON Aug 24 09:05:13 canidae kernel: [43925.893805] hid-generic 0003:534D:2109.000A: hiddev0,hidraw0: USB HID v1.10 Device [MACROSILICON] on usb-0000:00:14.0-1/input4 ==> /var/log/user.log <== Aug 24 09:05:13 canidae mtp-probe: checking bus 1, device 12: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-1" Aug 24 09:05:13 canidae mtp-probe: bus: 1, device: 12 was not an MTP device Aug 24 09:05:13 canidae mtp-probe: checking bus 1, device 12: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-1" Aug 24 09:05:13 canidae mtp-probe: bus: 1, device: 12 was not an MTP device ==> /var/log/daemon.log <== Aug 24 09:05:13 canidae rtkit-daemon[1452]: Supervising 7 threads of 2 processes of 2 users. Aug 24 09:05:13 canidae rtkit-daemon[1452]: Successfully made thread 155187 of process 1786 owned by '1000' RT at priority 5. Aug 24 09:05:13 canidae rtkit-daemon[1452]: Supervising 8 threads of 2 processes of 2 users. Not sure why it is trying to use it as a MTP device... Is this normal? I don't see anything about v4l which I would expect to see. Thanks -- Brian May &lt;brian(a)linuxpenguins.xyz&gt; https://linuxpenguins.xyz/brian/