用的Xcode7.0 按照开发文档书写单聊方法提示如下错误

Question

    __                        ________                __
   / /   ___  ____ _____     / ____/ /___  __  ______/ /
  / /   / _ \/ __ `/ __ \   / /   / / __ \/ / / / __  / 
 / /___/  __/ /_/ / / / /  / /___/ / /_/ / /_/ / /_/ /  
/_____/\___/\__,_/_/ /_/   \____/_/\____/\__,_/\__,_/   
                                                        
appid: W2Witcspgsd4DvNN9GJ5IzoI-gzGzoHsz
device_model: x86_64
carrier: 
access: 
app_version: 1.0
mc: 0C:4D:E9:9F:2D:35
sdk_version: v3.1.7.1
os: iOS
package_name: lanling.sensen.ChatDemo
sv: 1
language: en-US
display_name: ChatDemo
device_id: 433FC01C-95C9-4602-AA9A-07FED91545F3
is_jailbroken: 0
resolution: 750 x 1334
os_version: 9.0
timezone: 8
----------------------------------------------------------
2015-12-28 17:12:20.285 ChatDemo[965:52485] -[LCDatabase userVersion]: unrecognized selector sent to instance 0x7f967042bd90
2015-12-28 17:12:20.521 ChatDemo[965:52485] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[LCDatabase userVersion]: unrecognized selector sent to instance 0x7f967042bd90'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000010a0aaf65 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x00000001093cadeb objc_exception_throw + 48
    2   CoreFoundation                      0x000000010a0b358d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x000000010a000f7a ___forwarding___ + 970
    4   CoreFoundation                      0x000000010a000b28 _CF_forwarding_prep_0 + 120
    5   ChatDemo                            0x0000000108414a40 __39-[LCDatabaseMigrator versionOfDatabase]_block_invoke + 28
    6   ChatDemo                            0x0000000108419c83 __36-[LCDatabaseCoordinator executeJob:]_block_invoke + 60
    7   ChatDemo                            0x00000001083afc2c __30-[LCDatabaseQueue inDatabase:]_block_invoke + 55
    8   libdispatch.dylib                   0x000000010bb7149b _dispatch_client_callout + 8
    9   libdispatch.dylib                   0x000000010bb56051 _dispatch_barrier_sync_f_invoke + 393
    10  ChatDemo                            0x00000001083afbaa -[LCDatabaseQueue inDatabase:] + 164
    11  ChatDemo                            0x0000000108419c21 -[LCDatabaseCoordinator executeJob:] + 147
    12  ChatDemo                            0x00000001084149e0 -[LCDatabaseMigrator versionOfDatabase] + 144
    13  ChatDemo                            0x0000000108414ce1 -[LCDatabaseMigrator executeMigrations:] + 68
    14  ChatDemo                            0x000000010850cb6c -[LCIMConversationCacheStore migrateDatabaseIfNeeded:] + 128
    15  ChatDemo                            0x000000010850ca76 -[LCIMConversationCacheStore databaseQueueDidLoad] + 142
    16  ChatDemo                            0x0000000108531834 -[LCIMCacheStore databaseQueue] + 276
    17  ChatDemo                            0x000000010850e72f -[LCIMConversationCacheStore allExpiredConversations] + 66
    18  ChatDemo                            0x00000001085199a4 -[LCIMConversationCache cleanAllExpiredConversations] + 48
    19  ChatDemo                            0x0000000108510274 __26-[AVIMClient setClientId:]_block_invoke + 52
    20  libdispatch.dylib                   0x000000010bb50ef9 _dispatch_call_block_and_release + 12
    21  libdispatch.dylib                   0x000000010bb7149b _dispatch_client_callout + 8
    22  libdispatch.dylib                   0x000000010bb59c8b _dispatch_root_queue_drain + 1829
    23  libdispatch.dylib                   0x000000010bb59561 _dispatch_worker_thread3 + 111
    24  libsystem_pthread.dylib             0x000000010beb94f2 _pthread_wqthread + 1129
    25  libsystem_pthread.dylib             0x000000010beb7375 start_wqthread + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException