视频集成EaseU初始化会话列表为啥是空白,获取数据后崩溃？

 EaseConversationListViewController *list  = [[EaseConversationListViewController alloc]init];

    [self.navigationController pushViewController:list animated:YES];
 
//获取数据源
  NSArray *arr = [[EMClient sharedClient].chatManager getAllConversations];

    self.dataArray = [NSMutableArray arrayWithArray:arr];