No FBSession in Facebook iOS SDK 4.x

2 Solutions Collect From Internet About “No FBSession in Facebook iOS SDK 4.x”

Vincent is right, check [FBSDKAccessToken currentAccessToken] to determine if the user is logged in.

To check if the user logged in and if so, navigate to another view:

if ([FBSDKAccessToken currentAccessToken]) {
    // User is logged in
    [self performSelector:@selector(accessGrantedNavigation)
               withObject:nil afterDelay:0.0];

    [self performSegueWithIdentifier: @"segueLoginFB" sender: self];

To log out:
(although it doesn’t allow to change FB user. I think it is because Safari already takes care of that session and remains the same user.)

FBSDKLoginManager *manager = [[FBSDKLoginManager alloc] init];
    [manager logOut];

Hope it helps.