I have been running into this issue for a few months, so I have followed all of the trouble shooting steps, uninstalling and reinstalling the app with the latest version multiple times and any other (seemingly random) advice I have found on the boards.
I consistently run into this problem after 2 - 3 days of exclusively listening to the same radio station. (It is great when it works because it selects songs I want to listen to; however, when the radio station stops working, nothing brings it back.)
Repro:
1. Use Windows Desktop. I uninstalled and reinstalled from the Spotify site, so this is the most recently released/supported version. (The board will not let me post the actual app version.)
2. Select the "Radio" option from the top of the left pane.
3. Either create a new station or play a recommended station.
4. Listen for a while. You can close the app and reopen it, which is will do after several hours of playing. After reopening the app, you can select the station you found under the Recently Played list, which is how I have been reopening it.
4. Eventually, you will get to a point where the current song gets closer to the bottom of the playlist, and the message "More songs load as you listen" shows up below the playlist. When it works, the message will eventually go away and more songs will load. You will know you have hit the bug when that doesn't happen. The message never goes away, and no new songs will load. If you continue playing the songs in order, your playlist will just stop.
5. Select the Radio option from the left pane again. (You do not need to close and reopen the app.)
6. Select the Radio Station you were playing earlier. You will get the waiting icon and after a few seconds "This radio station cannot be started. Please try with something else." will show up. And you will forever see this message if you try to access that Radio Station.
Note that I tried running the workaround that you mentioned about playing the station in Spotify's Web Player; however, the broken radio stations do not show up in the player and there is no way to create or find a station. I tried playing a working radio station I listened to in the Desktop app on the Web Player, and nothing happens when click on the station.
