I had a similar issue in trying to set up my UR44C with Jamkazam. I found that by going to the dspMicFX UR-C app and clicking on “Loop Back” I was able to hear my inputs and also the sound from applications on my computer. Although I can now hear these things on my headphones I am still getting an error from Jamkazam stating that my device is not connected. I am getting a similar error on both my Mac and Windows 10 machines. I don’t get it as I believe I properly installed the drivers and I am obviously getting sound through the USB cable from the computer. I am not able to play a backing track in a session and can’t even get a solo session to work in Jamkazam. Has anyone been able to successfully use the UR44C with Jamkazam? I’m stuck and I have not been able to get a response from Jamkazam support. Any help would be appreciated. Thanks.