About Session Data

Mine isn't the unreachable code, it's the [] error. I'm trying to save to a session variable paymentinfo supplied by customer.

I'm writing a plugin for payment. Therefore in the payment info method of IPayment, I'm retrieving customValues

OK.  Then I think what I wrote here should work
https://www.nopcommerce.com/en/boards/topic/31082/how-i-can-put-and-get-session-value#273712