API problem or login information!?

[Cr3ativ]

Hello,
I have a problem with my PayPal Checkouts (from AliDropship plugin for Wordpress if helps). I succesfully paid (for a test order with other paypal account), and after this i was redirected to my website on "Fail order" page. I don't think is a problem with incorrect API credential, because i receive the money.
I have talked with developers, one tried to make an order, but fail. He said "it didn't even redirected to PayPal". Error in plugin-activities was "Gateway is damage" - Error code 10002. Authentication/Authorization Failed. You do not have permissions to make this API call. I searched for this PayPal error and find this "This error usually happens when permissions are set incorrectly in your PayPal account. To allow a third party to make API calls on your behalf, you must explicitly grant them permission to do so."
Another developer told me that "This is a common error that you might get if you are using Paypal Express Checkout, or Paypal Website Payments Pro. This means that there is something wrong with your login information that you are using to authenticate the connection with Paypal. As it is work properly on everybody elses accounts the issue is connected with your API credentials. Better to contact PayPal support regarding this issues I suppose."

[MTS_Andre]

Hi, in general the error 10002 can only arise for one of the following reasons:

1) wrong API credentials, check that you are using the LIVE credentials for the LIVE environment and SANDBOX for the test environment. Also verify that the API credentials have been copied and pasted correctly without any space before or after the value.

2) your cart/eCommerce is set to the wrong environment: check in your integration if it is set on LIVE or SANDBOX

3) wrong endpoint of your API calls, this would be in the code of your plugin.

Reference for endpoints: 

Endpoints

(if you are using an eCommerce solution check eventually with the module developer)

Also check that in your integration is not set the environment TEST anywhere that would bring you in a Sandbox environment rather than LIVE.
If with these checks it still does not solve your error then try to re-create a new set of API credentials.