The major update to Microsoft's flagship OS accidentally disabled many USB-connected webcams, including popular models such as Logitech's C920. It is the latest unintended side effect of the software update, which has also caused some devices to freeze up.
Feedback on Microsoft's community forums suggests the issue is affecting both consumers and enterprise users.
Microsoft expects to release a fix through Windows Update in September, but unlike the freezing bug, there is no official workaround, so for the meantime users will need to settle for Microsoft's apology and its explanation of what went wrong.
In the Anniversary Update, Microsoft wanted multiple apps, such as Windows Hello facial recognition, Microsoft HoloLens, and other products, to be able to access a webcam concurrently. Previously if, say, Skype was using the camera, these other services couldn't.
Hoping to prevent performance from becoming bogged down when multiple apps simultaneously decode media streams, Microsoft opted to stop USB-connected webcams from using MJPEG and H.264-encoded streams.
The Microsoft representative also apologised for failing to communicate these changes after its initial testing with partners and members of its Windows Insider program this January, and has promised better documentation in future.
"So yes, MJPEG and H.264 being decoded / filtered out is the result of a set of features we needed to implement, and this behavior was planned, designed, tested, and flighted out to our partners and Windows Insiders around the end of January of this year," wrote Mike M.
"We worked with partners to make sure their applications continued to function throughout this change, but we have done a poor job communicating this change out to you guys. We dropped the ball on that front, so I'd like to offer my apologies to you all," he added.
One forum member using the name Dacuda claimed to have millions of customers affected by issues related to the Windows 10 Anniversary Update.
Microsoft expects to address the MJPEG issue first, followed by a fix for H.264.