FBSDKShareDialog CRASH: [__NSCFString scheme]

Question

When executing this piece of code

FBSDKShareDialog *dialog = [[FBSDKShareDialog alloc] init];
dialog.fromViewController = viewController;
dialog.shareContent = content;
dialog.mode = FBSDKShareDialogModeFeedWeb;
dialog.delegate = self;
[dialog show];

the app crashes at [dialog show]; with this stack trace:

0   CoreFoundation                      0x2b9effa7 <redacted> + 150
1   libobjc.A.dylib                     0x3a0a0c8b objc_exception_throw + 38
2   CoreFoundation                      0x2b9f53a9 <redacted> + 0
3   CoreFoundation                      0x2b9f32c7 <redacted> + 714
4   CoreFoundation                      0x2b922ba8 _CF_forwarding_prep_0 + 24
5   uCiC                                0x003cf1ef +[FBSDKInternalUtility isBrowserURL:] + 22
6   uCiC                                0x0044c9f5 +[FBSDKShareUtility _validateNetworkURL:name:error:] + 64
7   uCiC                                0x0044b17d +[FBSDKShareUtility validateShareLinkContent:error:] + 176
8   uCiC                                0x0044ad71 +[FBSDKShareUtility validateShareContent:error:] + 284
9   uCiC                                0x004433ad -[FBSDKShareDialog validateWithError:] + 84
10  uCiC                                0x004431c5 -[FBSDKShareDialog show] + 36
11  uCiC                                0x002028c7 -[ICSocialSharer fbSharingInAppWebViewContent:inViewController:] + 306
12  uCiC                                0x002031f5 -[ICSocialSharer fbSharingForPostModel:inViewController:] + 2316
13  uCiC                                0x00203549 -[ICSocialSharer postMessageForModel:socialNetwork:inViewController:] + 568
14  uCiC                                0x000ea2e5 -[PostFotoViewController postSocial:] + 1528
15  UIKit                               0x2f0a2c4b <redacted> + 70
16  UIKit                               0x2f0a2bf1 <redacted> + 44
17  UIKit                               0x2f08d7e3 <redacted> + 582
18  UIKit                               0x2f0a265d <redacted> + 588
19  UIKit                               0x2f0a2337 <redacted> + 522
20  UIKit                               0x2f09bc11 <redacted> + 544
21  UIKit                               0x2f071e05 <redacted> + 196
22  UIKit                               0x2f2e86fb <redacted> + 14414
23  UIKit                               0x2f070819 <redacted> + 1352
24  CoreFoundation                      0x2b9b5d8f <redacted> + 14
25  CoreFoundation                      0x2b9b519f <redacted> + 218
26  CoreFoundation                      0x2b9b3805 <redacted> + 772
27  CoreFoundation                      0x2b8fff31 CFRunLoopRunSpecific + 476
28  CoreFoundation                      0x2b8ffd43 CFRunLoopRunInMode + 106
29  GraphicsServices                    0x333da201 GSEventRunModal + 136
30  UIKit                               0x2f0d1879 UIApplicationMain + 1440
31  uCiC                                0x0010d07d main + 108
32  libdyld.dylib                       0x3a652aaf <redacted> + 2

And the reason being: '-[__NSCFString scheme]: unrecognized selector sent to instance 0x187a8030'.

This happens since we've built using iOS9.

Now, the plist contains the correct schemes for FaceBookSDK 4.6 and also the AppTranspotPolicy is allowed.

Do you guys have any idea about how to fix this?

Thanks, D.

Answer 1

Apparently Facebook doesn't check if content urls are actually urls and they call [NSURL scheme] even though the object is an NSString.

So the content image url was written like this without any warning or problem from the compiler:

content.imageURL = [sharedData valueForKey:@"link"];  //which is an NSString

and after making it an NSURL like this

content.imageURL = [NSURL URLWithString:[sharedData valueForKey:@"link"]];

everything seems to work ok.

Pretty bad because the compiler doesn't complain but the app crashes at runtime. I will also file a bug on Facebook.

PS: I've wrote this here for anyone that will bump into this.