The wallet is working fine, the only problem is people attacking the network due to the low PoW network hashrate.

When the wallet detects an attack, it shows a checkpoint error - the checkpoint is what keeps Bittrex from sending your coins into a black hole or an attacker's wallet.

Once PoW is phased out in less than a week, the network will no longer be so easy to attack.

Please keep in mind that mining isn't there only to give people rewards - its primary function is to secure the network.  Given the extremely low hashrate of the network and the number of attacks that it has experienced, the fact that Bittrex has not yet been emptied out is a testament to Mindfox's professionalism and security-consciousness.  Too many developers opt for superficial fixes to make things seem like they're running, only to end up with the entire coin destroyed by thefts from users and exchanges.