Why I get a common error when trying to send an order?

 
even get this error when sending the order from the user interface~ Error Code: 2
 
Try to restart your terminal.
 
I restarted everything...
 

It was the problem of FxPro. I have confirmed with their help desk. It is OK now.

 
Thanks for the answer. So it was not my problem. I've been searching for the solution high and low at here 'How to fix a failed [Common error]'
Reason: