Hi, I have an application that reads in a bunch of values from an excel
application. Now this works fine on my computer but when I deploy it to a few
other computers, some of them return an 'Object Reference not set to an
instance of an object' error when I open it.

Here is my code....

Dim ExcelApp As Excel.Application
Dim ExcelBook As Excel.Workbook

ExcelApp = New Excel.Application
ExcelBook = ExcelApp.Workbooks.Open(Filename) ' error is here

I've narrowed it down to this only happening on computers with an older
version of Excel than I have currently installed. Does anyone know why this
happens and a solution that doesn't involve me installing an older version of
Excel?

Thanks,

Luc

You can build your app against a lower version of Excel and have it work
across all versions. See "Achieving Backward Compatibility with .NET
Interop: Excel as Case Study" -
http://www.devcity.net/Articles/163/1/article.aspx

--scott


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"Luc" wrote:

Hi, I have an application that reads in a bunch of values from an excel
application. Now this works fine on my computer but when I deploy it to a few
other computers, some of them return an 'Object Reference not set to an
instance of an object' error when I open it.

Here is my code....

Dim ExcelApp As Excel.Application
Dim ExcelBook As Excel.Workbook

ExcelApp = New Excel.Application
ExcelBook = ExcelApp.Workbooks.Open(Filename) ' error is here

I've narrowed it down to this only happening on computers with an older
version of Excel than I have currently installed. Does anyone know why this
happens and a solution that doesn't involve me installing an older version of
Excel?

Thanks,

Luc