Can you post a pic of your Settings / Audio. The logs show you are still trying to play to your Simaudio DAC.
Check Settings / Audio and make that the Ultra DAC is listed, that you have enabled it and given it a name. And then chosen it as the active endpoint. After all that, then try playing something to it.
I’m just a fellow user like you who made a couple of suggestions to try. However, I was able to download the file. So, I assume that Roon Support when they engage will be able to as well.
Thanks for your patience while our team navigates through each community thread. Following up on your issue, I was able to take a look at your account and see that your Nucleus and Meridian device were both online and active recently.
Are you still having issues? If so, please reproduce the issue and share the date, time, and track attempted to play.