facebook login issue - canOpenURL: failed for URL: "fbauth2:///" - error: "(null)"

When I click on login with Facebook button, it is opening safari browser and getting closed immediately. Noticed error on the console.

App delegate method:

func application(app: UIApplication, openURL url: NSURL, options: [String : AnyObject]) -> Bool {
    print("###### URL : ")
    print(url)
    print("###### App : ")
    print(app)
    print(options["UIApplicationOpenURLOptionsSourceApplicationKey"])
    return FBSDKApplicationDelegate.sharedInstance().application(app, openURL: url,  sourceApplication: options["UIApplicationOpenURLOptionsSourceApplicationKey"] as! String,
            annotation: nil)
}

2015-09-18 18:37:51.410 [21036:5050465] -canOpenURL: failed for URL: "fbauth2:///" - error: "(null)"

2015-09-18 18:37:51.417[21036:5050465] -canOpenURL: failed for URL: "fbauth2:///" - error: "(null)"
URL :
fb4554284912963222://authorize/?error_code=100&error_message=Invalid+Scope%3A+public&state=%7B%22challenge%22%3A%222ZmK6R5F05d%252F060TkCqj8SjPLjc%253D%22%2C%220_auth_logger_id%22%3A%223C79F2C8-61B9-470E-AE1B-E1C68435DB83%22%2C%22com.facebook.sdk_client_state%22%3Atrue%2C%223_method%22%3A%22sfvc_auth%22%7D&e2e=%7B%22init%22%3A145973.000512302%7D#=
App :

Optional(com.apple.SafariViewService)
nil
err:
Optional(Error Domain=com.facebook.sdk.core Code=8 "(null)" UserInfo={com.facebook.sdk:FBSDKGraphRequestErrorGraphErrorCode=100, com.facebook.sdk:FBSDKErrorDeveloperMessageKey=Invalid Scope: public, com.facebook.sdk:FBSDKGraphRequestErrorCategoryKey=0})

IDE : xcode 7
Language : Swift2
Facebook SDK : 4.6.0
Parse: 1.8.4

I have also verified .plist is having all keys which are required. Also verified the bundle identifier for typo mistakes. All look good. Facebook is active.

Any help?

I have the same warning, but in Facebook Docs there is an answer.

> This is an Xcode warning indicating the the canOpenURL: call returned false. As long as you have configured the LSApplicationQueriesSchemes entry in your plist as described above, you can ignore this warning

https://developers.facebook.com/docs/ios/ios9

The "-canOpenURL: failed for URL" warning is a red herring and simply means the FB app is not installed on the device/simulator you're running on.

It looks like you're requesting an invalid scope (aka permission) of "Public". Can you include your code that includes what permissions you are asking? public_profile is probably what you want (and what the SDK defaults to if none are provided).

More importantly, do NOT add fbauth2 to your CFBundleURLSchemes as that will break login flows. As Himanshu pointed out, those entries should be entered under LSApplicationQueriesSchemes in our plist.

If you're recompiling with iOS SDK 9.0, add the following to your application's plist if you're using a version of the Facebook SDK v4.6.0 or above:

   <key>LSApplicationQueriesSchemes</key>
   <array>
          <string>fbapi</string>
          <string>fb-messenger-api</string>
          <string>fbauth2</string>
          <string>fbshareextension</string>
   </array>

To prepare the facebook integration supported to iOS 9, go through Facebook Integraion for iOS 9 guidelines

To check version of facebook SDK, use below line of code:

   print("SDK version \(FBSDKSettings .sdkVersion())")

> This is an Xcode warning indicating the the canOpenURL: call returned > false. As long as you have configured the LSApplicationQueriesSchemes > entry in your plist as described above, you can ignore this warning.

Go to this Link Select Your App, And configure your info.plist

import And add this code in your AppDelegate

import FBSDKCoreKit .  
import FBSDKLoginKit

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
     return FBSDKApplicationDelegate.sharedInstance().application(application, didFinishLaunchingWithOptions: launchOptions)
}
    
func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
      return FBSDKApplicationDelegate.sharedInstance().application(app, open: url, options: options)
}

I have missed the importing FBSDKCoreKit. Later it started working on the simulator but not on the iPhone device.

Also noticed the following FAQ on the Facebook site. Why do I see console messages like > 'canOpenURL: failed for URL: "fb...://'

or ? This is a Xcode warning indicating the canOpenURL: call returned false. As long as you have configured the LSApplicationQueriesSchemes entry in your plist as described above, you can ignore this warning

Regarding not working on the iPhone device, please refer: https://stackoverflow.com/questions/32670555/parse-api-facebook-login-not-working-on-the-iphone-device/32670628

You need to add this method if your app is running on iOS9 or above.

- (BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary<NSString*, id> *)options {
return [[FBSDKApplicationDelegate sharedInstance] application:app
                                                  openURL:url
                                        sourceApplication:options[UIApplicationOpenURLOptionsSourceApplicationKey]
                                               annotation:options[UIApplicationOpenURLOptionsAnnotationKey]];

}

In case you need a Swift version:

@available(iOS 9.0, *)
func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
    return SDKApplicationDelegate.shared.application(app,
                                                     open: url,
                                                     sourceApplication: options[UIApplicationOpenURLOptionsKey.sourceApplication] as? String,
                                                     annotation: options[UIApplicationOpenURLOptionsKey.annotation] as Any)
}

I figured out my issue. It was just the syntax in loginButtonClicked function. The error message was leading me down the wrong path. Here is the working code.

@objc func loginButtonClicked() {
    self.login = FBSDKLoginManager()

    self.login.logIn(withReadPermissions: ["public_profile"], from: self, handler: {(result, error) -> Void in
        if error != nil {
            print("Process error")
        }
        else if (result?.isCancelled)! {
            print("Cancelled")
        }
        else {
            print("Logged in")
            DispatchQueue.main.async(execute: {
                let viewController:UIViewController = self.storyboard?.instantiateViewController(withIdentifier: "UITabBarController") as! UITabBarController
                self.present(viewController, animated: true, completion: nil)
            })
        }
        
        })
}

You have an extra "/" in your url "fbauth2:///".

Then you can see "error_message=Invalid+Scope" in the url, you should probably check the permissions of your app: https://developers.facebook.com/docs/facebook-login/permissions/v2.4

The issue is due to App Transport Security introduced in iOS 9.

There are two solutions, both deal with fixing your info.plist file

Here's a guide http://discoverpioneer.com/blog/2015/09/18/updating-facebook-integration-for-ios-9/