Open Word Document in .Net

Question

I'm trying to convert a C# Framework 4,.8 application to .Net 8.

If I include the line: dynamic MyWordApplication = new Microsoft.Office.Interop.Word.Application();

An error occurs: {"Could not load file or assembly 'office, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'. The system cannot find the specified file.":"office, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"}

I have added the Nuget package "Microsoft.Office.Interop.Word 15" but the error persists.

Answer 1

Hi,@zequion. Welcome to Microsoft Q&A. 

VSTO (Visual Studio Tools for Office) relies on the .NET Framework. COM add-ins can also be written with the .NET Framework. Office Add-ins cannot be created with .NET Core and .NET 5+, the latest versions of .NET. This is because .NET Core/.NET 5+ cannot work together with .NET Framework in the same process and may lead to add-in load failures. You can continue to use .NET Framework to write VSTO and COM add-ins for Office. Microsoft will not be updating VSTO or the COM add-in platform to use .NET Core or .NET 5+. You can take advantage of .NET Core and .NET 5+, including ASP.NET Core, to create the server side of Office Web Add-ins.

For more detailed explanation and usage, please refer to the official documentation(How to access Office interop objects - C# | Microsoft Learn)

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