Initial things to try:
- Check that the Dante Virtual Soundcard is turned on.
- Check that the network interface being used by Dante Virtual Soundcard is the correct one.
- Check the IP address settings of Dante Virtual Soundcard and ensure that the machine is in the same IP range as the Dante Controller.
- Try turning Firewall off (if possible).
- If you have multiple network interface running at the same time (including WiFi), try turning them off, and leave the Dante network interface as the only running.
macOS: If the machine has multiple network interfaces enabled, you may need to set the interface that Dante is using to the highest priority interface on the Mac. See the following tutorial for instructions: Change the order of the network services