Hello, You are right, something goes wrong during that process. Interestingly some orders are creating, some are not so the behaviour is not consistent. Now apart from these payment gateway module my website had a testimonial module as well, when that was enabled the same error was thrown showing that module (error attached), i am assuming that testimonial module was also involved during that call back process. WHen this module was disabled debug started showing the error with payment module.
Could this be due to some delay in that call back process which when gets timed out the error comes, and when no delay the order is created?