Checkout stuck in a loop!!

Hi there,

I have a problem with my payment gateway on my Opencart (2.3.0.2) installation. These are the symptoms:

1. Both payment gateways (PayPal Express & Sagepay) failed on Friday. When a customer tries to Checkout, they are forced into a loop of where they are returned to the beginning of the checkout process repeatedly.
2. The logs are giving these errors:
2018-05-12 16:39:39 - PHP Notice: Undefined index: L_LONGMESSAGE0 in /var/www/vhosts/example.com/httpdocs/catalog/controller/extension/payment/pp_express.php on line 1345
2018-05-12 16:39:39 - Unable to create Paypal session{"":""}

2018-05-12 16:40:20 - PHP Notice: Undefined variable: data in /var/www/vhosts/example.com/httpdocs/catalog/model/extension/payment/sagepay_server.php on line 424

I find it a bizarre coincidence that both gateways fail at the same time. No changes to the configuration have been done during this time. Any ideas thanks?

It's a problem with the PHP cURL function curl_exec not returning any data. Switching on the payment module debug message my give you more of an idea why it's failing. You could also ask you host if they have made any changes to the server that would affect it.