If you are using one of our publisher apps, please make sure that the app is running, and says that it is connecting successfully both to your broker and to FX Blue. For example, if you are using the Publisher EA for MetaTrader 4, please make sure that the EA is running on a chart and that Expert Advisors are enabled in MT4.
If you are using account sync, then please check your settings on the account sync page. Brokers do occasionally change their server settings, and you may find (in MT4 particularly) that the details of your account have changed - e.g. your account is now on a different server, as reported by the Tools/Options in MT4.