Hi,
as you might have a noticed a coin you are listing called Yenten (YTN) has pretty much dropped to zero. This is due to the latest wallet (2.0.1) having a bug (CVE-2018-17144) that allows for coins to be created out of thin air. A couple weeks ago there were already 500000000 bogus coins in circulation and a lot of them ended up on exchanges (including yours). Yentens current supply is about 12000000. Just check your sell orders and you will realize that there is a major problem (you have more coins for sale than technically exist).
Long story short: The Yenten 2.0.1 chain can safely be considered unfixably broken and then coins on it are certainly worthless. Most of the community (including all major pools) has switched to 1.3.1 (currently running at 190kh/s easily overpowering the dwindling hashrate of 2.0.1) because it is unaffected by said bug and it's chain is still healthy.
Also since the original developer (Conan) has gone missing (nobody including various exchanges has been able to reach him and he ignored pull requests fixing the fatal bugs for months now - not that it matters anymore with the current state of the 2.0.1 chain) a group consisting of several people (currently bubus, ohashi3d and POOPMAN from the official Yenten discord) has formed aiming to continue the Yenten 1.3.1 chain and replace the faulty 2.0.1 release in form of Yenten 3.x. This effort has been well received by the community (you can check responses on the official discord and bitcointalk for proof) and a new website has been created at
https://www.yentencoin.info/.
I am contacting you on behalf of said group. We are collectively using the email account i am writing you from. We ask you to politely consider to switch your Wallet to version 3.x which can be found at
https://github.com/yentencoin/yenten. We realize this is a problematic action for you. On one hand we are not the original developers while on the other hand switching involves resetting current balances (please don't make the same mistake Stex did with simply switching to the 1.3.1 chain and later realizing most of the coins on their site don't exist there making them unable to pay people who decided to withdraw). We propose you halt trading and force people to withdraw to their 2.0.1 wallets before switching to 3.x. While all this takes effort on your part you should realize the current situation is not only hurting Yenten but also your reputation. We have to tell people on a regular basis that the coins they bought are worthless and their trust has been misplaced. In the unfortunate event that you decide against switching to 3.x you should at least delist Yenten. While not an optimal outcome it would still be better for everyone involved than continuing to allow the fake coins to be traded.
For reference please see trade.multicoins.org which already allows coins on the 1.3.1/3.x chain to be traded under the temporary acronym of YNTN. Hopefuly this temporary acronym can be changed to original YTN acronym soon but for this to happen other exchanges would need to stop trading the broken 2.0.1 coins under this name (by either switching to 3.x or if this is not possible for some reason delisting). We think it's obvious that some kind of action needs to be taken. If not for the good of Yenten then at least to secure the best possible experience for your users.
If you have any questions or concerns please don't hesitate to contact us either at this email address or on the official Yenten discord. We would be more than happy to work with you.
Best regards,
the Yenten community development team