Error in exporting excel file using sysoperation framework

Use jobclass to run without errors:
But use the processOperation method in SysOperationServiceBase
There will be an error:
An internal error has occurred. Please contact your system administrator.

code show as below:
//Filename fileFullName,fileName;
//FileInfo tmpfile,t1,t2;
//ExcelRange cell;
//ExcelWorksheet cells;
//MemoryStream memoryStream = new MemoryStream();
//tmpfile = new System.IO.FileInfo(“C:\temp\test\test.xlsx”);
//ExcelPackage filePackage = new ExcelPackage(tmpfile);
//memoryStream = filePackage.Stream;

     //fileFullName ='C:\\temp\\textexcel.xlsx';
     //filepackage.SaveAs(new FileInfo(fileFullName));
     //file::SendFileToUser(memoryStream,'tstest.xlsx');

There us no executable code at all - everything is commented out.

Sorry, the commented out code is the executed code

First of all, why do you think that there should be any file at c: drive on the particular AOS server? If you didn’t put it there in the same process, then the whole thing doesn’t make sense, because your code may be executed on a completely different server. And if you did, then what’s the point? Why do you need to put it into file and immediately read it from there? It seems to me that you still don’t understand how cloud works.
Then you forgot to escape backslashes in new System.IO.FileInfo(“C:\temp\test\test.xlsx”). You need either @“C:\temp\test\test.xlsx” or “C:\\temp\\test\\test.xlsx”.
In general, when you have problem with code, use the debugger to find out what’s going on, e.g. which line of code is throwing an error, the type of exception and so on.

file::SendFileToUser(memoryStream,‘tstest.xlsx’);
After executing this line of code,
There will be an error message, but it will not trigger my debugger

Hmm, are you saying that you’re unable to debug your code at all? Or what do you mean by “it will not trigger my debugger”? You need to start the program with debugging, or attach debugger to the running process. It won’t happen magically by itself.
Also, could you please address my first point?