The Windows 10 Anniversary Update, aka version 1607, has been found to leave many webcams inoperable. The update prevents the use of webcams in applications such as Skype and Open Broadcaster Software (OBS), along with all manner of custom CCTV programs. Extremely popular hardware, such as Logitech's C920 and C930e cameras, in conjunction even with Microsoft's own Skype, will fail to properly broadcast video.
People first noticed the issue earlier this month. But it's only within the last couple of days that the exact cause became clear via a post by Brad Sams on thurott.com.
Microsoft has said that a fix is in development, but has not yet said when that fix will be distributed.