Mine did the same thing the other day. It started after I updated Cakewalk by Bandlab to v2019.11. Whenever I'd close the DAW, it would stay running in the process manger & the 16x08 would hang as well. Then I tried to turn it off & back on, but it couldn't be recognized for a few seconds until Windows gave the unknown device error. I had a similar "Unknown USB Device error" in the Device Manger. I can't remember exactly what the error was titled, but I think it was under the "Universal Serial Bus controllers" section. If I remember correctly, I fixed it by clicking "uninstall device" in the Device Manager error & rebooted. Windows reinstalled the proper drivers after that. It's not giving me any more unknown device errors, but now I'm having a lot of BSOD's when trying to run Cakewalk, usually after I try to close it. The bug check usually points to WDF_VIOLATION (wdf01000.sys). I'm not sure if it's Cakewalk, Windows, or the US-16x08, but considering the huge amount of trouble I've had with this interface over the past few years, I'm gonna assume it's the culprit. I've been trying to troubleshoot it for a couple days now. Good luck...