An exchange rate cannot be found for exchange rate type Average between currencies SAR and USD on exchange date

I found another solution for this error. Instead of setting up a dummy exchange rate, if you remove triangulation, then this will also fix the error:

  1. General Ledger > Setup > Currency > Currencies and locate the EUR currency. You should see that the Reference currency for triangulation box is checked.

  2. to remove the checkmark from the Reference currency for triangulation box go to General Ledger > Setup > Currency > Denomination Currencies and remove the denominational currencies listed there. Once complete remove the check box from the Reference currency for triangulation check box.