Microsoft Office Excel cannot access the file on IIS

Question

I have a web service method which search string in given Excel file and return its status. This is working okay in VS project. But when I public same web service in IIS its throwing error: I'm working on Windows7 machine

System.Runtime.InteropServices.COMException: Microsoft Office Excel cannot access the file 'C:\inetpub\wwwroot\MyFirstWebService\App_Data\Results.xlsx'. There are several possible reasons:

• The file name or path does not exist.
• The file is being used by another program.
• The workbook you are trying to save has the same name as a currently open workbook.


string filePath = Server.MapPath("~") + @"\App_Data\Results.xlsx";
            xlApp = new Excel.Application();
            xlWorkBook = xlApp.Workbooks.Open(filePath, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
            xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

I have checked filePath C:\\inetpub\\wwwroot\\MyFirstWebService\\App_Data\\Results.xlsx and it is okay.

I also tried with few online solutions like below, But its not fixed yet:

Create directory "C:\Windows\SysWOW64\config\systemprofile\Desktop " (for 64 bit Windows) or 
"C:\Windows\System32\config\systemprofile\Desktop " (for 32 bit Windows)

Set Full control permissions for directory Desktop (for example in Win7 & IIS 7 & DefaultAppPool set permissions for user 
    "IIS AppPool\DefaultAppPool")

Why it's working on VS not on IIS? my user account got admin right too, wonder why its not working.

Thanks

Answer 1

I was having issue while reading the Excel from MVC application hosted on IIS. Two things are important for accessing the Excel from IIS.

1. Must have "C:\\Windows\\SysWOW64\\config\\systemprofile\\Desktop". ie Desktop folder in SysWOW64 folder, System32 folder for 32 bit.
2. Assign full access to IIS_IUSRS user on Desktop folder.

It`s kind of weired, not sure why this is required but worked for me.

Answer 2

I ran into this problem and couldn't find a solution anywhere. There were multiple issues at play here. The IIS application was on a 64 bit Windows server 2008 but the installed version of office was a 32 bit version.

This article pointed me in the right direction:

http://blogs.technet.com/b/the_microsoft_excel_support_team_blog/archive/2012/11/12/microsoft-excel-does-not-appear-in-dcom-configuration-snap-in.aspx

However, instead of security i had to change the identity of the Microsoft Excel Application in Dcom Config to be an administrator instead of the launching user.