There are several factors that can affect the MT4 platforms ability to connect to the trading system. Before attempting to identify a connection problem inside the platform, first be sure that the login details, including the server address are correct.
"Please note that when copy pasting the details from the registration email we send you, it is very common to mistakenly copy extra 'space' characters, so please check the number of characters entered after you paste"
If all login details are correct, check the connection status of the platform. This is in the bottom right corner and is shown by a series of colored vertical bars scored diagonally followed by a series of numbers, eg. 1056/2.
'No Connection' is displayed if the problem is internet connection based;
'Invalid Account' is displayed if the problem is related to the credentials used.