To fix an unconfirmed blockchain transaction, you can try several methods. First, wait a bit longer, as low transaction fees often cause delays. If the wait is too long, use a "Replace-By-Fee" (RBF) option, which allows you to resend the transaction with a higher fee to prioritize it. Alternatively, use a transaction accelerator service, which submits your transaction to miners for faster processing. If the transaction remains unconfirmed for an extended period, it may eventually be returned to your wallet, allowing you to attempt the transfer again with a higher fee.