In PRODUCTION mode, if your buyer gets an error message such as:
|An error occurred during the payment request, please make sure that the posted parameters match the ones specified in the documentation.|
It becomes impossible to make the payment and the transaction is definitively lost.
You will receive an e-mail notification containing the form that the gateway was unable to process and the value of the invalid field.
We invite you to check the following reason(s) to resolve the issue:
|The specified MID only supports recurring payments|
|You have requested the creation of a single payment (vads_page_action field).
However, the specified MID (vads_contracts) only supports recurring payments.