NullReferenceException when uploading large xml file

从 Renci.SshNet.SftpClient.InternalUploadFile 开始，以提供的堆栈跟踪作为切入点。在服务器上通过任务复现大型 XML 上传，并将其与小文件和本地运行进行比较；当确定不完整上传和 NullReferenceException 的原因，并且有经过验证的修复或回归测试覆盖时，即视为完成。

System.AggregateException: One or more errors occurred. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at Renci.SshNet.SftpClient.InternalUploadFile(Stream input, String path, Flags flags, SftpUploadAsyncResult asyncResult, Action`1 uploadCallback)
--below is our internal stack
at ....UploadFile(Stream input, String path)
at ......Common.Ftp.SftpClient.Upload(Byte[] buffer, String fileName, String remoteFolder, Boolean useDefaultRemoteFolder, Boolean usePassive)
at ......Common.Ftp.FtpService.UploadFileToSftp(Byte[] file, String remotePath, String fileName)
at System.Threading.Tasks.Task.Execute()
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at System.Threading.Tasks.Task.Wait(TimeSpan timeout)
at

Hi

When we try to upload large xml file through tasks in our server, NullReferenceException pops up and made the uploaded file incomplete. The file indeed was uploaded, but it was broken and missed half of the file content.

This issue can not be reproduced in our dev local and only occurred in server, also it won't happen for small xml files(with same encoding and path)

SSH version we used in our company here is 2020.0.2

Could you pls advise what's the possible root cause for it since we could get further callstack details for it