ASP.NET - Error Excel

En la maquina de desarrollo la exportación a excel funciona correctamente, pero cd la subo al servidor al exportar me devuelve el siguiente error:

Object reference not set to an instance of an object.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
Excel.Workbooks.Open(String Filename, Object UpdateLinks, Object ReadOnly, Object Format, Object Password, Object WriteResPassword, Object IgnoreReadOnlyRecommended, Object Origin, Object Delimiter, Object Editable, Object Notify, Object Converter, Object AddToMru, Object Local, Object CorruptLoad) +0
SETCOM.ConfiguracionMtto.formHelicopteros.btnExportExcel_Click(Object sender, ImageClickEventArgs e) +206
System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) +109
System.Web.UI.WebControls.ImageButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +69
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +18
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain() +1277

Alguien sabe de q error se trata?
Gracias

Al parecer la biblioteca de objetos de Excel que usaste en la maquina de desarrollo no es la misma que la del servidor. Chequea las versiones de Excel que estas usando en las dos maquinas