My blockchain.info wallet shows that I received 225 ETH on 16 October 2017. Until today 18 October 2017 my ETH balance is zero. Can someone explain me please what is happening?
If you don't have any outgoing transaction, ETH should still be in your wallet.
As TheCoinFinder suggested you, have you checked on etherscan.io the transaction?
If the transaction still is not confirmed, you could eventually "delete" it by making another transaction with the same "nonce" with a higher gas. As two transactions with the same nonce cannot coexist, the first transaction will be dismissed.
Let us know