This issue has been also observed when a donation form has been copied from another donation form. As such, the issue may be rooted to cached payment settings that are copied from a donation form that cause this error to appear. To resolve this error, create a brand new donation form instead of creating a copy.
This also has been resolved by creating a new Merchant Account in NetCommunity using the same information contained in the merchant account that no longer works.
- Create a new merchant account and give it a different name
- Enter the required fields and save ( If you don't know the password/transaction key you will have to generate a new one in your authorize.net account)
- - Go to the form that the merchant account is being used on and edit it
- - Select the new merchant account under the payment options and save
- - Refresh the form and submit a transaction.
- - Update your forms to use the new merchant account.