Hi,
  I created a Excel object using interop.excel 9.0. the code is as simple as

protected Excel.ApplicationClass oExcel = null;
oExcel = new Excel.ApplicationClass();

Now this works well in my development environment but in production it's not working and throwing a 'Null reference Exception'. It's Obvious that it's an environment issue .

My questions are :

1.Does the Excel interop try to access something in important windows folders like 'System32' for which i don't have .. or in simple words can this be a disguised Access violation error?
2. if it's not a access violation erro then is there any way to get more details form this 'Null refernce exception' because i don't get a damn of what null reference is there ..

Can anyone help me out?



thanks @ regards
Deepak

If it was a permissions issue you would get an 'Access Denied' error as opposed to Null Reference.

Also, Microsoft does not recomened using Interop to access Excel as it was never designed to work this way, alternatively you may want to follow the examples on these pages:

http://SteveOrr.net/articles/ExcelExport.aspx
http://SteveOrr.net/articles/ExportPanel.aspx

Also if you do go about coding it the way you have done above, id suggest using Excel.Application as opposed to Excel.ApplicationClass. (The why's can be found on this MSDN blog)

http://blogs.msdn.com/ptorr/archive/.../05/67872.aspx

Hth.

"The one language all programmers understand is profanity."

Thanks dparsons for Ur comments .. but i want to add more points

Ur link http://SteveOrr.net/articles/ExcelExport.aspx
showed me the way to create excel in many ways but as "steve" says all ways of creating excel won't suit everyone .. tht's what has happened to me ..
there are two methods which use the Response object to create excel but creating excel in that way pops up the mssg asking the client to save or open .. this is my problem because i want want to client to know that there is a excel that is getting created and i want all the stuff to be in the back ground :-(


And finally the Excel.Application also failed..
can U just suggest me a good way to derive meaningful error messages from this exception.. currently i log the error mssg in a text file but it's helping me no where

even the stack trace is not helping me .
and Ur suggestion for Application() instead of applicatioclass() .. here my point of argument is why use "Application" if it's in turn gonna use application class

thanks @ regards
Deepak