Enter a conversion rate for the customer profile. (AR-856815)

Summary:

When I enter an invoice in foreign currency I get the above error. Customer profile class (site level) for the customer is set in the late charges tab with the currency and conversion rate.

Content (required):

Which configuration am I missing?

Version (include the version you are using, if applicable):

.

Code Snippet (add any code snippets that support your topic, if applicable):

.