This happens when one of the LND's cert file, macroon file or address are missing. Can you check if they are present in: /lnd/tls.cert and /lnd/data/chain/bitcoin/mainnet/admin.macaroon If not then you might have to configure the Umbrel's lightning app first to make sure it runs properly (Alby Hub uses LND from Umbrel's lightning app so that should be running)