NSInvalidArgumentException occurred!

[Sweeper777]

I am using Swift so I don't know whether that is the problem.

So I have a UITextField and an SZTextView (a subclass of UITextView). I wrote these two lines in viewDidLoad:

NBEmojiSearchView().installOnTextView(txtContent)
NBEmojiSearchView().installOnTextField(txtTitle)

just like you did in README.md

When viewDidLoad was called, I got this exception and the app crashes:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'data parameter is nil'
*** First throw call stack:
(
    0   CoreFoundation                      0x0081d494 __exceptionPreprocess + 180
    1   libobjc.A.dylib                     0x02bf5e02 objc_exception_throw + 50
    2   CoreFoundation                      0x0081d3bd +[NSException raise:format:] + 141
    3   Foundation                          0x013e4455 +[NSJSONSerialization JSONObjectWithData:options:error:] + 67
    4   NBEmojiSearchView                   0x002b2ed4 -[NBEmojiManager loadEmoji] + 356
    5   NBEmojiSearchView                   0x002b2c1d -[NBEmojiManager init] + 125
    6   NBEmojiSearchView                   0x002b4b30 -[NBEmojiSearchView manager] + 96
    7   NBEmojiSearchView                   0x002b582b -[NBEmojiSearchView tableView:numberOfRowsInSection:] + 91
    8   UIKit                               0x01aa12f5 -[UISectionRowData refreshWithSection:tableView:tableViewRowData:] + 3174
    9   UIKit                               0x01aa5e82 -[UITableViewRowData numberOfRows] + 98
    10  UIKit                               0x0183ed39 -[UITableView noteNumberOfRowsChanged] + 141
    11  UIKit                               0x0183e1f4 -[UITableView reloadData] + 2189
    12  NBEmojiSearchView                   0x002b509d -[NBEmojiSearchView setFont:] + 141
    13  NBEmojiSearchView                   0x002b456d -[NBEmojiSearchView init] + 221
    14  MyApp                         0x00074db1 _TTOFCSo17NBEmojiSearchViewcfT_S_ + 33
    15  MyApp                         0x00074996 _TFCSo17NBEmojiSearchViewCfT_S_ + 86
    16  MyApp                         0x0006f7ce _TFC11PocketDiary21DiaryEditorController11viewDidLoadfT_T_ + 2718
    17  MyApp                         0x0006f952 _TToFC11PocketDiary21DiaryEditorController11viewDidLoadfT_T_ + 34
    18  UIKit                               0x0189bb72 -[UIViewController _sendViewDidLoadWithAppearanceProxyObjectTaggingEnabled] + 44
    19  UIKit                               0x018a0692 -[UIViewController loadViewIfRequired] + 1384
    20  UIKit                               0x018a0ab1 -[UIViewController view] + 35
    21  UIKit                               0x018fb935 -[UINavigationController preferredContentSize] + 212
    22  UIKit                               0x01871eec -[UIPresentationController preferredContentSizeDidChangeForChildContentContainer:] + 67
    23  UIKit                               0x0186dafc __56-[UIPresentationController runTransitionForCurrentState]_block_invoke + 105
    24  UIKit                               0x018b0e3b __40+[UIViewController _scheduleTransition:]_block_invoke + 18
    25  UIKit                               0x016dd7cb _runAfterCACommitDeferredBlocks + 337
    26  UIKit                               0x016f3a60 _cleanUpAfterCAFlushAndRunDeferredBlocks + 103
    27  UIKit                               0x01701ef6 _afterCACommitHandler + 102
    28  CoreFoundation                      0x0072f75e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 30
    29  CoreFoundation                      0x0072f6be __CFRunLoopDoObservers + 398
    30  CoreFoundation                      0x0072503c __CFRunLoopRun + 1340
    31  CoreFoundation                      0x00724846 CFRunLoopRunSpecific + 470
    32  CoreFoundation                      0x0072465b CFRunLoopRunInMode + 123
    33  GraphicsServices                    0x05de0664 GSEventRunModal + 192
    34  GraphicsServices                    0x05de04a1 GSEventRun + 104
    35  UIKit                               0x016cfeb9 UIApplicationMain + 160
    36  MyApp                         0x0006cb51 main + 145
    37  libdyld.dylib                       0x045a6a25 start + 1
    38  ???                                 0x00000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

What causes this? Is it because I'm using Swift?