Type of message:  This is an internal message for MediusGo. 

Cause: The invoice exchange rate differs more than +/- 0.2 from the rate entered in the system.

Action: Just re-choose the Currency Code from the drop down in the Invoice head to connect the invoice currency to the correct Currency register.

If none of this solves the problem, contact the MediusGo Customer Center via the support button on the invoice or our Customer portal.