ios - My App crash on iPad before even application:didFinishLaunchingWithOptions: -

my app crashing following crashlog when ran on ipad. work fine on iphone devices. might notice, crash while trying setup window. have searched everywhere don't see such issue in other topic.

thanks help.

*** terminating app due uncaught exception 'nsinvalidargumentexception', reason: '*** setobjectforkey: object cannot nil (key: nsparagraphstyle)' *** first throw call stack: (     0   corefoundation                      0x000000010e38ff35 __exceptionpreprocess + 165     1   libobjc.a.dylib                     0x000000010e028bb7 objc_exception_throw + 45     2   corefoundation                      0x000000010e296998 -[__nsdictionarym setobject:forkey:] + 968     3   uikit                               0x000000010ca99d2d -[uilabel _setlinebreakmode:] + 529     4   uikit                               0x000000010cb7a572 -[uibuttonlabel setlinebreakmode:] + 93     5   uikit                               0x000000010cb86e5c -[uibutton _setuptitleviewrequestinglayout:] + 308     6   uikit                               0x000000010cb7ed15 -[uibutton titlelabel] + 51     7   uikit                               0x000000010cd3c6d8 -[uizoomviewcontroller loadview] + 476     8   uikit                               0x000000010c9f67f9 -[uiviewcontroller loadviewifrequired] + 75     9   uikit                               0x000000010c9f6c8e -[uiviewcontroller view] + 27     10  uikit                               0x000000010cd3bfa4 -[uizoomviewcontroller init] + 78     11  uikit                               0x000000010cd39eeb -[uiclassiccontroller _setupwindow] + 544     12  uikit                               0x000000010cd39b7c +[uiclassiccontroller sharedclassiccontroller] + 140     13  uikit                               0x000000010c8e47dd -[uiapplication _handleapplicationactivationwithscene:transitioncontext:completion:] + 666     14  uikit                               0x000000010c8e42ae __88-[uiapplication _handleapplicationlifecycleeventwithscene:transitioncontext:completion:]_block_invoke + 138     15  uikit                               0x000000010c8e4215 -[uiapplication _handleapplicationlifecycleeventwithscene:transitioncontext:completion:] + 349     16  uikit                               0x000000010c8cf31a -[uiapplication scene:didupdatewithdiff:transitioncontext:completion:] + 486     17  uikit                               0x000000010c8cedb8 -[uiapplication workspace:didcreatescene:withtransitioncontext:completion:] + 336     18  frontboardservices                  0x000000011064f612 __56-[fbsworkspace client:handlecreatescene:withcompletion:]_block_invoke_2 + 265     19  frontboardservices                  0x000000011065e2a3 __31-[fbsserialqueue performasync:]_block_invoke + 16     20  corefoundation                      0x000000010e2c553c __cfrunloop_is_calling_out_to_a_block__ + 12     21  corefoundation                      0x000000010e2bb285 __cfrunloopdoblocks + 341     22  corefoundation                      0x000000010e2bb045 __cfrunlooprun + 2389     23  corefoundation                      0x000000010e2ba486 cfrunlooprunspecific + 470     24  uikit                               0x000000010c8ce669 -[uiapplication _run] + 413     25  uikit                               0x000000010c8d1420 uiapplicationmain + 1282     26  edyn                                0x0000000109704323 main + 115     27  libdyld.dylib                       0x000000010ebd2145 start + 1     28  ???                                 0x0000000000000001 0x0 + 1 ) 

edit 1

the problem more complicated thought. here have done.

1. implemented method swizzling around [uibuttonlabel setlinebreakmode:] can see causing use nil linebreakmode. found out if linebreakmode set else nslinebreakbywordwrapping crash.
2. to temporary make work forcing linebreakmode nslinebreakbywordwrapping not big deal in case because label never seens in app.

edit 2

after fixing issue linebreakmode, getting same issue time [uilabel setshadow:]. note crash on label didn't change shadow attributes (color, offset or blurradius). same issue time paragraphstyle

which mean can't not keep using approach seems broken in what's happening.

edit 3

when change deployment target of app universal, don't have of above issues.

i overriding 2 functions in category , guess what? function seems called ios before control of app in appdelegate. , reason on ipad return nil. removing category fixed problem.

+ (id)systemfontofsize:(cgfloat)sz {     return [uifont fontwithname:@"helveticaneue-regular" size:sz]; } + (id)boldsystemfontofsize:(cgfloat)sz {     return [uifont fontwithname:@"helveticaneue-bold" size:sz]; }