[angelflames1337]

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"There has to be a webbrowser installed on your system for the first authentication dialog"


There is a small workaround to try if you have another client which actually does have a browser:
1. install the spotify client on a pc with a browser
2. open the spotify client and accept the authentication request in the browser.
3. now, on the filesystem navigate to kodi userdata\addon_data\plugin.audio.spotify and copy the cache file to the same location on your pi

I tried this. But when I open my C:\Program Files (x86)\Kodi\userdata in my PC where my Spotify Kodi is running fine, the only files in there is RssFeeds.xml, no other files.

Edit: OK I figured this out, the folder was a wrong one. Now that I copied the myname.cache file to my Pi OSMC Kodi folder, the Spotify open up. But now it wont play from the start, and each songs only lasts 30 seconds before switching to other songs.
Edit2: I also got "Login error: Platform not supported for playback, continuing without playback support." when launching Spotify Kodi.