If you get an exchange error a quick refresh of the asset you were trying to send AND a refresh of the asset you were expecting to receive tends to fix this problem.
For example if you were exchanging Ethereum for Dash refresh BOTH your Ethereum and Dash wallets. Many times the asset you are expecting to receive (in this example Dash) will show up after a manual refresh.
The refresh process is the same for all assets. For example, the steps to refreshing Ethereum are shown below.
Although this process is rare it does happen ocasionally if your assets lose a connection to the network. This simple fix not only brings your wallet back in synch it also properly refreshes all your transaction history to get you to the most up-to-date state. Exchanges can not take place if your wallet is not up to date with the current network state.