Sadly, no major OS update passes without some issues being caused somewhere, and in the case of the Fall Creators Update, Elgato's PCIe capture card, the HD60 Pro, is affected in a pretty major way.
The driver for the card can go into an endless reboot loop rendering it completely useless. So, Elgato has pumped out a quick fix but is emploring its customers to update their card's firmware and drivers before installing the Fall Creators Update.
As some of you may be aware, the Windows 10 Fall Creators Update is out, and as with any major OS update, low-level changes can have effects on hardware. Unfortunately, this time the HD60 Pro is affected.
The issue: With the Windows 10 FCU (Fall Creators Update), the HD60 Pro driver will get stuck in a reboot loop and the firmware will be blank.
The solution: We have released a new software update, 3.60.108, which includes a new driver that fixes the issue.
If you've already grabbed the Fall Creators Update, Elgato is advising rolling back first, then installing its new drivers and firmware. I have an HD60 Pro and haven't seen these issues myself, but they're clearly widespread enough given the message.