Some brokers use symbol prefix and/or suffix in fx symbols (e.g XXXYYY.mini .XXXYYY). To allow for the EA to take trades, user should under the prefix and/or suffix in the Symbol settings
(e.g. EURUSD_X user should go to EA settings, under the section 'symbol settings' and add (_X ) in symbol suffix area)
Moreover, Brokers have different names when it comes to Metals, Energies.... Gold might be written as GOLD or XAUUSD. User should enter correspondent Symbol for each asset.