I am having the same problem. Just received my (metal V2.0) Flirc yesterday. I downloaded and installed the GUI today (3.9.8). After the install I plugged in the Flirc to my Windows 10 64bit (1709 build 16299.192) and after in installed the hardware the GUI still says disconnected. I tried uninstalling the Flirc device from Windows and uninstalling the software and reinstalled as administrator and reinstalled the device but still no go.
Help.