Your real account hasn't been activated yet. In order to activate your account for trading, certain sum of money must be deposited to your account. Demo accounts do not require activation. Contest accounts are activated automatically at the beginning of contest.
If there is not enough free funds ('Free margin') available on your trading account for opening a position, you will receive such error. Please check from Trader's Calculator what amount of margin is required for a particular trading instrument and calculate the standard or hedged margin for all of your opened positions. If you see that there is not enough money to open a new position, you can close some of your existing positions or deposit additional funds to your trading account.