After upgrade to magento from 2.1.7 to 2.2.1 the paypal method is not showing in payment method list in checkout.
main.CRITICAL: PayPal NVP gateway errors: Security header is not valid (#10002: Security error). Correlation ID: 77ca004062046. Version: 72.0. [] []
main.CRITICAL: PayPal gateway has rejected request. Security header is not valid (#10002: Security error). {"exception":"[object] (Magento\Framework\Exception\LocalizedException(code: 0): PayPal gateway has rejected request. Security header is not valid (#10002: Security error). at /vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:111)"}
main.DEBUG: array (
'url' => 'https://api-3t.paypal.com/nvp',
'getPalDetails' =>
array (
'METHOD' => 'getPalDetails',
'VERSION' => '72.0',
'USER' => '****',
'PWD' => '****',
'SIGNATURE' => '****',
'BUTTONSOURCE' => 'Magento_Cart_Community',
),
'response' =>
array (
'TIMESTAMP' => '2017-12-18T09:39:49Z',
'CORRELATIONID' => '77ca004062046',
'ACK' => 'Failure',
'VERSION' => '72.0',
'BUILD' => '39206242',
'L_ERRORCODE0' => '10002',
'L_SHORTMESSAGE0' => 'Security error',
'L_LONGMESSAGE0' => 'Security header is not valid',
'L_SEVERITYCODE0' => 'Error',
),
) [] []
PayPal all-in-one solution I have enable in payment method.