@klaxons welcome to the Community. This type of error typically implies a network issue. How is your Windows computer connected to your router, via WiFi or Ethernet cable. If via WiFi, can you temporarily use an Ethernet cable for the connection, and if the error goes away with the cabled connection we can focus on the WiFi network connection.
Thanks @klaxons. Is it possible to swap your Ethernet cable or the router port to which the cable is connected? Also, are your firewall settings on Windows set to allow Roon and Roon Server per these guidelines:
Is the error message related to files streamed from the internet, local files, or both?
Welcome to the Roon Community! Sorry to hear about your playback issues. @Robert_F shares a common issue that may very well help you - let us know if it does!
If you still run into playback issues, can you please use the directions found here and send over a set of Roon Server logs to our File Uploader?