Getting an error screen?
Sometimes this might occur because the coin list is not in-sync with our servers. To re-sync the coin list simply search and add any coin to the Watchlist.
Not getting any errors but the coin is not visible after adding the transaction?
You might have the "Hide small balances" option enabled which can hide coins which have very small holdings (less than 0.2% of your total portfolio value). Try disabling the option under Settings -> Other options.
If either solution does not work for you please contact us at firstname.lastname@example.org and mention that your issue and that you've tried both the above solutions.