If you are receiving an "Unknown error" when attempting to redeem on Solana, it is likely that something is preventing the transaction from going through. The best way to get help with this is to join the Solana Discord and ask in the Portal support channel. The team there can help you troubleshoot the issue and provide guidance on how to resolve it. It is also recommended to double-check that you have entered the correct information and that you have enough SOL tokens in your wallet to cover the transaction. If you still experience issues after trying these steps, the Portal support team will be able to provide further assistance.