Auth:check() always returns false

I tried googling but didn't get the solution yet.

I'm trying to know whether user is authenticated or not into the view file by using

1. Auth::check() always returns false
2. Auth::User() always returns NULL

Tried posts:

1. It says to place domain to null that's already there.

2. Some posts say to edit into the kernel.php, how safe is it?

Any help will be appreciated. Thanks