On a Windows laptop: 1. Insert USB key. 2. Go to https://webauthn.bin.coffee/ 3. Click "Create Credentials" and do NOT perform USB verification. 4. Close laptop. 5. Wait until laptop goes to sleep - around 30-60 seconds. 6. Open laptop and log in. 7. Return to Firefox. * Abort message is displayed, as expected 8. Interact with the browser/page: * Refresh page * Click on "Get Credentials" * Navigate to another page Result: Browser is unresponsive. However, if you remove USB key, it regains its stability and works again. Expected: Browser should function normally, as it currently does on Mac.

Matt, I don't have a Windows laptop but I suspect this might have had the same root cause as bug 1400940. Can you please try again with the latest Nightly? Thanks!

Issue still happens with today's Nightly on Windows 10.

I've used my desktop Win 10 machine (with all the latest updates installed) and tried to reproduce this, without luck. Firefox doesn't hang and I can even "resume" a WebAuthn request if it wasn't cancelled yet, or just start a new one and complete it. There were no changes to the Windows code since you reported this issue so I assume you can still reproduce. Does this reliably reproduce for you? Every time or just sometimes? Does Chrome have a similar issue? (I don't expect it to but you never know...)

I can still repro with Nightly 59.0a1 from 2017-11-20. I think the key is how long you wait until the computer goes to sleep. If I close the laptop and reopen within 20 seconds, all is fine. If I wait 60 seconds, then I see the problem as originally reported.

Just a small update: I have (temporarily) acquired an Acer laptop with Windows 10, our Quantum reference HW, and have tried to reproduce this for a while, without luck unfortunately. I wonder, is this something specific to Matt's machine? Or to the YubiKey itself? Matt, when you find the time, could you please check whether you can reproduce with another Win10 machine? And/or with another YubiKey model? What YubiKey model do you have? That would be the easiest factor for me to change and re-test.

Thanks for the effort on this, Tim. I am using the blue Yubikey U2F model pictured here [1]. I am also using a fairly old Lenovo ThinkPad laptop that I acquired from the IT department. It's the only Windows hardware I have access to at the moment. I guess I'd need to track down more hardware to test on. In the interim, I think this bug is easily deferred, as it appears to affect limited/older hardware, requires an edge case to reproduce, and is easy enough to remedy if the user just unplugs the key. [1] https://www.yubico.com/products/yubikey-hardware/fido-u2f-security-key/

Matt can't reproduce this anymore. Let's close this as WFM and see if it resurfaces in the future.