PayPal IPN Bad Request 400 Error

Question

Using the PayPal IPN, I keep getting an error 400.

I have been making the script send me emails of $res to see what the response is, inside of the

Answer 1

I had the same problem and the best thing is to use the paypal sample code... It works perfectly then : https://www.x.com/developers/PayPal/documentation-tools/code-sample/216623