FileNotFoundException was unhandled: Could not load file or assembly 'ESRI.ArcGIS.Version, Version='

Last Published: April 25, 2020

Error Message

Running an application from Microsoft Visual Studio 2008, Visual Basic 2008 Express Edition or Visual C# 2008 Express Edition on a 64-bit machine displays the following error message:“FileNotFoundException was unhandled
Could not load file or assembly ‘ESRI.ArcGIS.Version, Version=, Culture=neutral, PublicKeyToken=8fc3cc631e44ad86’ or one of its dependencies. The system cannot find the file specified.”


When running a Visual Studio application, the default Common Language Runtime (CLR) in the Microsoft Visual Studio environment is 'Any CPU'. This default setting must be changed on 64-bit computers to compile the assemblies with the 32-bit, x86 compatible CLR.

Solution or Workaround

Change the default Platform Target CPU to allow applications to run on 64-bit machines.

For Microsoft Visual Studio:
1. Right-click on the solution in the Visual Studio Solution Explorer and open the Properties window.
2. Click the compile tab: Visual Basic, or the 'build' tab: Visual C#.
3. For Visual Basic, click the 'Advanced' tab.
4. Select x86 as the Target CPU (Visual Basic) or Platform Target (Visual C#).
5. Rebuild the solution.

For Microsoft Visual Basic or Visual C# Express Editions:
1. Open the solution in the Express Edition.
2. Click File > Save All. Save the project to a different location.
3. Using Windows Explorer, browse to the newly saved project and open the project file (.csproj or .vbproj) with a text editor.
4. Insert the text <PlatformTarget>x86</PlatformTarget> into the 'Debug|AnyCPU' and 'Release|AnyCPU' sections.

5. Save the project file.
6. Open the solution in the Express Edition. Build and run the application.

    Article ID:000010800

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