On February 1st, 2019 Melon (MLN) went through a token migration (Token Swap). All MLN funds held on Kraken at the time were automatically swapped. If you held MLN in your own personal wallet before the token migration took place you should swap your tokens before depositing to Kraken or any other exchange.

All old MLN tokens deposited to Kraken will not be credited and are unrecoverable. Further information and instructions on the "Token Migration" can be found here: https://medium.com/melonport-blog/mln-token-migration-event-96b1c8003876

If you have any further questions or concerns feel free to reach out to us by submitting a support ticket here