Going to Special:SecurePoll/dump/$id$ (where $id$ is the election ID) gives you a dump of the election if it is configured as an encrypted election and the decryption key is provided in the database. If the election is configured as not being encrypted, the dump page should then provide the data dump; however, because in such a scenario no decryption key exists, it will complain about that and refuses to provide a dump.

Instead, it should provide an unencrypted dump of the election configurations and votes.