paypal express checkout =>Error: Security header is not valid

Question

Error : Security header is not valid Array

(
    [TIMESTAMP] => 2014%2d04%2d29T07%3a24%3a29Z
    [CORRELATIONID] => 6af6749c848d6
    [ACK] => Failu         


        

Answer 1

I had this issue because my login contained "+"(plus) sign. Finally I manually decoded it to "%2B" as described here http://www.zen-cart.com/showthread.php?80849-Plus-sign-%28-quot-quot-%29-in-user-name-causes-security-header-failure-in-Paypal-Express-Checkou and the issue gone.