paypal SDK integration objective c - ios

Question

I'm trying to integrate Paypal to my objective c project.
After the Paypal login screen appears and i enter my login data and login success and this view pops to the previous view which should display the logged client data the application crashes giving me the following error
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSPlaceholderDictionary initWithObjects:forKeys:count:]: attempt to insert nil object from objects[0]'
*** First throw call stack:
(
0 CoreFoundation 0x0000000113defd85 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x00000001137f7deb objc_exception_throw + 48
2 CoreFoundation 0x0000000113cec23e -[__NSPlaceholderDictionary initWithObjects:forKeys:count:] + 318
3 CoreFoundation 0x0000000113cfe5bb +[NSDictionary dictionaryWithObjects:forKeys:count:] + 59
4 AppCreator 0x000000010d890e1e +[PPZebraUI text:withAnnotation:] + 810
5 AppCreator 0x000000010d875c87 -[PPFundingOption titleForDisplay] + 318
6 AppCreator 0x000000010d8b187f -[PPPaymentFundingOptionSelectionCell refreshContent] + 653
7 AppCreator 0x000000010d8b0bfc -[PPPaymentAttributeSelectionCell initWithViewController:withTitle:withPickerTitle:withDataSource:] + 1293
8 AppCreator 0x000000010d88db04 -[PPSelectPayMethodViewController paymentAttributeSelectionCells] + 310
9 AppCreator 0x000000010d8d4601 -[PPSelectPayMethodViewControllerIOS7 updateTableToConfirm:] + 977
10 AppCreator 0x000000010d8d416e -[PPSelectPayMethodViewControllerIOS7 refreshTable:] + 100
11 AppCreator 0x000000010d8d4229 -[PPSelectPayMethodViewControllerIOS7 viewDidAppear:] + 87
12 UIKit 0x000000010f41d335 -[UIViewController _setViewAppearState:isAnimating:] + 830
13 UIKit 0x000000010f41dcb8 -[UIViewController _endAppearanceTransition:] + 262
14 UIKit 0x000000010f45886f -[UINavigationController navigationTransitionView:didEndTransition:fromView:toView:] + 1290
15 UIKit 0x000000010f44e630 __49-[UINavigationController _startCustomTransition:]_block_invoke + 233
16 UIKit 0x000000010fcaa4c8 -[_UIViewControllerTransitionContext completeTransition:] + 101
17 UIKit 0x000000010f2658a3 __53-[_UINavigationParallaxTransition animateTransition:]_block_invoke95 + 834
18 UIKit 0x000000010f32d53e -[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:] + 644
19 UIKit 0x000000010f30a7ff -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 241
20 UIKit 0x000000010f30abae -[UIViewAnimationState animationDidStop:finished:] + 80
21 QuartzCore 0x000000010f12e3c8 _ZN2CA5Layer23run_animation_callbacksEPv + 308
22 libdispatch.dylib 0x000000011440b3eb _dispatch_client_callout + 8
23 libdispatch.dylib 0x00000001143f31ef _dispatch_main_queue_callback_4CF + 1738
24 CoreFoundation 0x0000000113d490f9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
25 CoreFoundation 0x0000000113d0ab99 __CFRunLoopRun + 2073
26 CoreFoundation 0x0000000113d0a0f8 CFRunLoopRunSpecific + 488
27 GraphicsServices 0x0000000115780ad2 GSEventRunModal + 161
28 UIKit 0x000000010f27cf09 UIApplicationMain + 171
29 AppCreator 0x000000010d3251df main + 111
30 libdyld.dylib 0x000000011444092d start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
I tried the SDk in separated application and it works perfectly .this error happens when i add the sdk to my project .
can anyone please help me what can be causing this error

Answer 1

I found out that problem was in another Library i was using .
It had a function which override the
"preferredFontForTextStyle" in the "UIFont" class
that was causing the problem for me.
in case anyone facing that kind of unjustified crash , try to remove all the other classes one by one to check that the error is not caused by conflict with another line in a far class