这是我在Stackoverflow上的第一篇文章，所以如果我做错了，请告诉我。
我有一个Swift iOS应用程序，我从Crashlytics获得了以下崩溃：
Fatal Exception: NSInvalidArgumentException
0 CoreFoundation 0x184f0afe0 __exceptionPreprocess
1 libobjc.A.dylib 0x18396c538 objc_exception_throw
2 CoreFoundation 0x184dec898 CFStringConvertNSStringEncodingToEncoding
3 Reserv 0x1003500c0 -[ICMDataManager updateInboxWithConversation:]
4 Reserv 0x10037a714 __83-[ICMNativeConversationContentViewController replyToConversationWithBlocks:upload:]_block_invoke
5 Reserv 0x100358958 __69+[ICMHTTPBridge replyToConversation:withBlocks:upload:success:error:]_block_invoke_2
6 libdispatch.dylib 0x183dc29e0 _dispatch_call_block_and_release
7 libdispatch.dylib 0x183dc29a0 _dispatch_client_callout
8 libdispatch.dylib 0x183dc75e8 _dispatch_main_queue_callback_4CF
9 CoreFoundation 0x184eb90c8 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__
10 CoreFoundation 0x184eb6ce4 __CFRunLoopRun
11 CoreFoundation 0x184de6da4 CFRunLoopRunSpecific
12 GraphicsServices 0x186851074 GSEventRunModal
13 UIKit 0x18b0a1c9c UIApplicationMain
14 Reserv 0x1000824d4 main (UserPlacesModule.swift:23)
15 libdyld.dylib 0x183df559c start
然而，UserPlacesModule.swift：23是以下行：
21 protocol UserPlacesModuleProtocol {
22
23 }
24
25class UserPlacesModule : ModuleProtocol{
这根本没有用。那么有什么可以导致这个问题的建议吗？
感谢您的帮助。