The recent Windows 10 Anniversary Update can break webcam support in Elgato Game Capture HD software, in certain situations.
For more information:
For example, certain cameras might start to have a very low frame rate.
A solution is to download the attached file, DisableFrameServer_64bit.reg, and use it to edit your registry.
1) Download DisableFrameServer_64bit.reg
2) Right click on DisableFrameServer_64bit.reg, and choose Run As Administrator
3) Follow the instructions, and offer a confirmation of the changes
4) Restart your PC