Then it appeared on blockchain, waited for a long time to be confirmed
But then it's not seen on the chain
Also the coins are gone
wtf dude?
Have you seen your transaction included in blockchain or in transaction pool. Probably you have seen it in tx pool and you transaction was too big sized, so it was rejected by miners and you receive your XDN back.
All users you should understand the logic of XDN and any other CryptoNote coin:
There is a tx median. XDN default tx median size = 32kb. So each block that is below that size (sum of all transactions in it) will have BASE_BLOCK_REWARD and transactions in that block will be included in blockchain any way. Sometimes blocks can be bigger than 32kb, in that case BASE_BLOCK_REWARD will be decreased to protect network and blockchain. Usually biggest size of transaction that can be included in blockchain = 1.3*current_effective_median_size, or +30%.
Some "hero pools", sometimes can include bogger transactions, but block rewards will be under big penalty.
By some reasons (E.G. structure of inputs/outputs of your "mining" transactions) you may produce BIG sized transaction.
If you transaction if 2x time > than current tx median size, you transaction will never be included in blockchain, and will be rejected by all miners.
Next week we will solve that problem, by rejecting all BIG transaction on wallet-client level.
As for now, you should just produce smaller sized transactions, by lowering coins amount or lowering mixin count. sometimes even 1000XDN amount can cause Big transactions, if your mining transactions was too small E.G. if you receive this 1000XDN with 10000 small 0.1 XDN transactions.
That sounds progressive.