If the app has discovered your Renderer/Chromecast but has connection problems when you play a song, you can try the following:
- Disconnect then reconnect to the device via the 'Select Playback Device' screen by selecting 'This Device' and then select your network device again
- Exit the Hi-Fi Cast app via the Exit menu item. Then open the app and try again.
- Exit the Hi-Fi Cast app by swiping it from the 'Recent Apps' screen (the notification in the status bar should also disappear). Then open the app and try again.
- Clear the playback queue AND hit Refresh from the Media Library screen menu (this will clear data cached from the Media Server). This may be required after media server configuration changes.
For Chromecast devices you can also try the following:
- Disconnect then reconnect to the Chromecast via the 'Select Playback Device' screen by tapping the 'Disconnect' button (if it is visible) and then the 'Connect' button
- Open the Google Home App, go to the devices screen (via the button on the right side of the toolbar) and tap STOP CASTING. Then try playing the current track again (if the Play/Pause button in Hi-Fi Cast is showing as a buffering icon then long-press it to get the Play button back).