When PayPal API “Transaction cannot complete.” error is caused by the customer’s PayPal wallet, even PayPal insiders don’t know the cause, so you have to contact credit card companies or banks.

With the PayPal API, even PayPal employees don’t know the cause of errors like:

• "L_SEVERITYCODE0": "Error"
• "L_SHORTMESSAGE0": "Transaction cannot complete."
• "L_LONGMESSAGE0": "Instruct the customer to retry the transaction using an alternative payment method from the customers PayPal wallet. The transaction did not complete with the customers selected payment method."

So customers need to directly contact the company of the payment information registered with PayPal.

(Example) PayPal API Response

   "response": {
     "TIMESTAMP": "2017-12-13T01:23:45.000Z",
     "CORRELATIONID": "700c4464c60c9",
     "ACK": "Failure",
     "VERSION": "204",
     "BUILD": "39206242",
     "L_ERRORCODE0": "10417",
     "L_SHORTMESSAGE0": "Transaction cannot complete.",
     "L_LONGMESSAGE0": "Instruct the customer to retry the transaction using an alternative payment method from the customers PayPal wallet. The transaction did not complete with the customers selected payment method.",
     "L_SEVERITYCODE0": "Error"
   },

That’s all from the Gemba that wants to know the detailed cause of PayPal errors.