This error is occurring because the Organization Contact is set as the Donor of a Donation.  The Donation ID is identified in the error by the number that appears as 006***************.

An Organization Contact cannot be the Donor of a Donation, but rather a Household Contact or Donor Proxy must be set as the Donor instead.  This error can be fixed by changing the Donor of that Donation to a Household Contact or Donor Proxy.