Hi Leon,
Could you share how your program calls LibreOffice?
I have set the bug's status to 'NEEDINFO'. Please change it back to
'UNCONFIRMED' once the question has been answered

I'm very glad to receive your email. I really appreciate.
I post my brief main code. I use C# to call the LibreOffice.exe to  change my file. But just keep running and I didn't see the any error message.
Here is my code below.

// Just use C# Process to execute the  LibreOffice.exe
            startInfo.FileName = ConfigurationManager.AppSettings["LibreOfficeExePath"];
            startInfo.WorkingDirectory = outputDir;
            startInfo.WindowStyle = ProcessWindowStyle.Hidden;
            startInfo.Arguments = string.Format(" -headless -convert-to {1} 
                                  {0}", inputFilePath, extensionParameter);
            startInfo.RedirectStandardError = true;
            startInfo.RedirectStandardOutput = true;
            startInfo.Verb = "runas";

 using (Process exeProcess = Process.Start(startInfo))
            {
                var errorMessage = exeProcess.StandardError.ReadToEnd();
                var streamMessage = exeProcess.StandardOutput.ReadToEnd();
                File.AppendAllText(@"E:\BackUp\BackUpLog.txt", 
                $@"\r\n{errorMessage}\r\n{streamMessage}");
                exeProcess.WaitForExit();
            }

My program just keep waiting the LibreOffice.exe return some command. 
This code ====>  Process.Start(startInfo)  into the LibreOffice.exe to change file then never reach this code ====>  exeProcess.WaitForExit();
 I think my program doesn't receive any response, so just keep waiting for LibreOffice.exe return some information.

This my problem I posted in stackoverflow but no one can fix this problem. Please check this link. Hope you can get more information.
https://stackoverflow.com/questions/47824861/use-c-sharp-process-to-shift-the-file-to-odflibreoffice

Hi Leon,
Does it work if you call LibreOffice from the terminal ?

Hello,

I'm not sure that what the terminal  mean is?
I can run normally in local when I develop the program. My program can call the LibreOffice work correctly in local. but I release my program to the server IIS.
I can see my program call the LibreOffice work normally. I can see the LibreOffice running in the task manager. but my program just keep run. because my program doesn't receive the LibreOffice  return a result or any error message.
Just keep running...

Best Regards,
Leon.

The problem is no one here has a setup like you, and won't be able to tell why it's working differently in IIS. The best chance for you is to build yourself a debug build from the current development branch, attach a debugger to it while it's running in IIS (if that's possible), and see where it stalls during exit, and what differs from normal execution.

Dear Bug Submitter,

Please read this message in its entirety before proceeding.

Your bug report is being closed as INSUFFICIENTDATA due to inactivity and
a lack of information which is needed in order to accurately
reproduce and confirm the problem. We encourage you to retest
your bug against the latest release. If the issue is still
present in the latest stable release, we need the following
information (please ignore any that you've already provided):

a) Provide details of your system including your operating
   system and the latest version of LibreOffice that you have
   confirmed the bug to be present

b) Provide easy to reproduce steps – the simpler the better

c) Provide any test case(s) which will help us confirm the problem

d) Provide screenshots of the problem if you think it might help

e) Read all comments and provide any requested information

Once all of this is done, please set the bug back to UNCONFIRMED
and we will attempt to reproduce the issue. Please do not:

a) respond via email 

b) update the version field in the bug or any of the other details
   on the top section of our bug tracker

Warm Regards,
QA Team

MassPing-NeedInfo-20181009