Not getting Travel Error on OpenLevel Failure

I am trying to openlevel client from gamelift, if my Openlevel fail I am not getting any Travel Error

In Brief: - I am Trying to Host a Game on gamelift , it works Properly but if I block some Ports Or I have Firewall ON, then the Client will not be able to properly load the next Level. In this case, I am not getting any Travel Error, I want to handle this case

Or

in Other words, I want to Know, How to know whether OpenLevel fails or not ?