Logitech C310 Webcam Not Recognized

Apple only provides the drivers for the USB ports. They do not make any drivers required by the camera, additionally. If the camera uses USB then it must be designed to work with the standards deployed drivers provided by Apple.

You can always try reinstalling Sierra on the off chance it was a defective download or you upgraded a dysfunctional system.

Fix Non-Working Sierra Installations

Try each of these in order. Test to see if the computer is working properly:

1. Reset the PRAM
2. Reset the System Management Controller (SMC)
3. Start the computer in Safe Mode, then restart normally. This is slower than a standard startup.
4. Repair the disk by booting the from the Recovery HD. Immediately after the chime hold down the Command and R keys until the Utility Menu appears. Choose Disk Utility and click on the Continue button. Select the indented (usually, Macintosh HD) volumeentry from the the side list. Click on the First Aid button in the toolbar. Wait for the Done button to appear. Quit Disk Utility and returnto the Utility Menu. Restart the computer from the Apple Menu.
5. Reinstall OS X by booting from the Recovery HD using the Command and R keys. When the Utility Menu appears select Reinstall OS X then click on the Continue button.
6. Erase and Install Sierra. Use Disk Utility to erase the drive, then return to the Utility Menu and select Reinstall OS X. Click on the Continue button.

Contact Logitech's tech support. The camera may be incompatible.