My Logitech C920 was working fine in 8.11.0.4; I saw the "A new update is available…" notification in the UI so updated via my package manager. Upon launching the new 8.13.0.2 version, my webcam could not be found. Restarting the computer didn't help, neither did uninstalling and reinstalling skypeforlinux. I have since downgraded to 8.11.0.4 and my camera is working again.
➜ ~ neofetch
.-/+oossssoo+/-. kris@devbox
`:+ssssssssssssssssss+:` -----------
-+ssssssssssssssssssyyssss+- OS: Ubuntu 17.10 x86_64
.ossssssssssssssssssdMMMNysssso. Model: EX58-UD3R
/ssssssssssshdmmNNmmyNMMMMhssssss/ Kernel: 4.13.0-21-generic
+ssssssssshmydMMMMMMMNddddyssssssss+ Uptime: 23 mins
/sssssssshNMMMyhhyyyyhmNMMMNhssssssss/ Packages: 3530
.ssssssssdMMMNhsssssssssshNMMMdssssssss. Shell: zsh 5.2
+sssshhhyNMMNyssssssssssssyNMMMysssssss+ Resolution: 1920x1080, 1920x1080, 1920x1080
ossyNMMMNyMMhsssssssssssssshmmmhssssssso DE: Xfce
ossyNMMMNyMMhsssssssssssssshmmmhssssssso WM: Xfwm4
+sssshhhyNMMNyssssssssssssyNMMMysssssss+ WM Theme: Numix Daily
.ssssssssdMMMNhsssssssssshNMMMdssssssss. Theme: Numix Daily [GTK2], Breeze [GTK3]
/sssssssshNMMMyhhyyyyhdNMMMNhssssssss/ Icons: Numix-Circle [GTK2], Breeze [GTK3]
+sssssssssdmydMMMMMMMMddddyssssssss+ Terminal: xfce4-terminal
/ssssssssssshdmNNNNmyNMMMMhssssss/ Terminal Font: Source Code Pro 9
.ossssssssssssssssssdMMMNysssso. CPU: Intel i7 920 (8) @ 2.793GHz
-+sssssssssssssssssyyyssss+- GPU: NVIDIA GeForce GTX 650 Ti Boost
`:+ssssssssssssssssss+:` Memory: 3376MiB / 12010MiB
.-/+oossssoo+/-.
➜ ~ lsusb
[…]
Bus 002 Device 002: ID 046d:082d Logitech, Inc. HD Pro Webcam C920
[…]