I have been using it since roon 1.6, but since updating to 2.0, I cannot play music properly.
I did a clean install of everything and even with about 10 songs, it still does not play music properly.
I would appreciate if you could tell me how to deal with this problem.
The error you are seeing is often caused by networking issues.
Roon 2.0 increased the demands on the network.
As suggested above, having your Core on wifi could be the problem.
If you are able to, at least temporarily for troubleshooting, try connecting your Core to your router via an Ethernet cable and see if that resolves this.
If you are already using Ethernet for your Core there are some other things to try.
Let us know.
Bonded Ethernet most likely which means your using more than one cable to get faster speeds and redundancy if one goes down often called aggregation, most Nas allow this.