Live Magento store, works fine through PayPal payments. But when we add Authorize.net, transactions won't complete. We get the following error.
Response Reason Code: 13
Response Reason Text: The merchant Login ID is invalid or the account is inactive.
Called Authorize.net - the account is active
Cut and pasted API Login ID
Generated and cut and pasted new Transaction key
Attached screenshot from Magento admin.