PayPal Express error 10002 security header not valid

[imaginationtoy]

Hello!

I am getting this error every time I try to complete an order in sandbox mode:

We are sorry for the inconvenience. The PayPal account authentication settings are not yet set up, or the API security information is incorrect. We are unable to complete your transaction. Please notify the store owner so they can correct this problem. (10002) 10002 Security error - Security header is not valid

I have double checked my API username, password and signature several times, and they are exactly right.

I am using Zen Cart 1.3.9d. I have a Website Payments Pro with Express Checkout account with PayPal, and according to PayPal, there is nothing wrong with my account. As far as I can see, I have my Zen Cart PayPal settings configured right as well.

I have attached the log file I received for my last attempt at this.

I appreciate any help with this!

[DrByte]

If you're going to play in the sandbox, you need to get new API credentials from your sandbox account to enter into your store.

Then to go live again you'll need to get your live API credentials and put those back into your store again.

[imaginationtoy]

Thank you so much! Working perfect now!

[s_mack]

How'd you fix it? I'm in the same boat and i keep getting that error. I am using the info from my sandbox account, not live. I wasn't at first but figured that out and now I still get the same error.

[s_mack]

Nevermind... dumb. I was doing my admin on one server, but testing the front end on a different server. Once I noticed that... all is fine. My bad.