modprobe: ERROR: could not insert 'v4l2loopback': Unknown symbol in module, or unknown parameter (see dmesg)

Question

I am trying to set up virtual v4l2 devices on an AWS EC2 instance. I did apt install for v4l2loopback-dkms and v4l2loopback-utils.

I get the following error when i try to set up devices with

sudo modprobe v4l2loopback device=8

modprobe: ERROR: could not insert 'v4l2loopback': Unknown symbol in module, or unknown parameter (see dmesg)

If I check dmesg: [87243.295525] v4l2loopback: Unknown symbol video_ioctl2 (err -2)

[87243.295553] v4l2loopback: Unknown symbol v4l2_ctrl_handler_init_class (err -2)

[87243.295582] v4l2loopback: Unknown symbol video_devdata (err -2)

[87243.295605] v4l2loopback: Unknown symbol v4l2_ctrl_new_custom (err -2)

[87243.295623] v4l2loopback: Unknown symbol video_unregister_device (err -2)

. . .

uname -a

5.4.0-1055-aws #58~18.04.1-Ubuntu SMP Wed Jul 28 03:04:50 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

Could you please help me on this?

Answer 1

Using AWS EC2 - ubuntu 20.04 LTS, I installed:

sudo apt -y install v4l2loopback-dkms v4l2loopback-utils linux-modules-extra-$(uname -r)

followed by:

sudo modprobe v4l2loopback

worked for me