BC-You must specify Realized Losses Acc. in Currency Code

 If this happens on any journal screen, and you know things are setup correctly, most likely a user has entered two different values in the "Amount" and "Amount($)" fields.

Amount = Original customer currency

Amount($) = Your system base currency

If you enter two different values, an exchange rate is calculated and stored for that line.

You must delete the line and re-enter it, ensuring that you fill in the "Amount" field only, and allow the "Amount($)" field to populate automatically