Front line support is fairly useless on this. I’d love to be able to help figure this out. Can someone on the Mycroft dev team check to see if their app is still authorized? INVALID_CLIENT seems to point to the request being rejected by Spotify because it doesn’t trust the client id that we’re returning to them for the auth request.
i too see the exact same error. looks like the the client ID (client_id=5509ac5c42cc45d7b4625d0b851a0f1e) on the redirect from the connect button in the spotify skill is no longer valid? Would love to get an answer to Tatorzot and others question on this from the devs. tx!