ios集成easeui问题

easeSDK用cocopod集成，easeUI直接拖过来，编译没有问题，但是一加上这句好就报错。
 
 
  EaseMessageViewController *chatVC = [[EaseMessageViewController alloc] initWithConversationChatter:@"sunjie1" conversationType:EMConversationTypeChat];

    [self.navigationController pushViewController:chatVC animated:YES];