Fixing MSB4064 When Building VS2010 Web Solutions with NAnt

Originally published on 2010-03-09; fully revised and updated.

This article covers a legacy build issue that still appears in older enterprise codebases: a solution with web projects compiles in Visual Studio 2010, but fails from the command line through NAnt with Copy task errors. You will learn what is happening, why the temporary workaround does not hold, and how to align NAnt configuration with the installed .NET 4 runtime.

Symptoms and error signature

In the reported case, the build succeeded in the IDE and failed from NAnt with these errors:

Error MSB4064: The "Retries" parameter is not supported by the "Copy" task.
Error MSB4063: The "Copy" task could not be initialized with its input parameter.Code language: JavaScript (javascript)

This pattern typically indicates that the command-line build is loading a different MSBuild/.NET toolchain than the one used by Visual Studio.

Why changing project files to 9.0 is only a temporary workaround

A workaround was found by editing project files to point from the v10.0 web application build targets back to 9.0. That allowed compilation once, but reopening in VS2010 reverted those edits. So it is not a stable fix for active development.

Troubleshooting workflow

flowchart TD
    A[Build works in Visual Studio 2010] --> B[NAnt command line build fails]
    B --> C{MSB4064 or MSB4063?}
    C -- yes --> D[Target NAnt to .NET 4 tools]
    D --> E[Add .NET 4 framework section in nant.exe.config]
    E --> F[Set vendor to Microsoft]
    F --> G[Match version token to installed Framework directory]
    G --> H[Run NAnt build again]
    C -- no --> I[Investigate other build errors]

Resolution options compared

Step-by-step fix for the reported scenario

1) Confirm installed .NET Framework directories

dir C:\Windows\Microsoft.NET\FrameworkCode language: CSS (css)

Use this to verify the exact v4.0 folder/version available on the build machine.

2) Update NAnt to use .NET 4 framework definitions

The original report required extending nant.exe.config with .NET 4 framework entries because the existing config did not support the new target yet.

3) Add the missing vendor attribute and align version tokens

<!-- Example pattern inside the .NET 4 framework entry in nant.exe.config -->
<framework ... vendor="Microsoft" ... />

<!-- Update copied values to match what exists on disk -->
v4.0.20506 -> v4.0.30128Code language: HTML, XML (xml)

The key point is not the sample numbers themselves, but that your config must match the actual framework version present on the server.

4) Re-run the command-line build

nant

Common pitfalls

• Relying on project-file downgrades that VS2010 will overwrite.
• Copying a .NET 4 config block but missing required attributes such as vendor.
• Using hard-coded framework version tokens that do not match the machine.
• Changing build config without backing up nant.exe.config first.

For legacy pipelines, keep Visual Studio version, target framework, and NAnt framework mappings explicitly documented and version-controlled to prevent environment drift.

Rajesh Kumar

I’m Rajesh Kumar, a DevOps, SRE, DevSecOps, Cloud, and Platform Engineering expert passionate about sharing practical knowledge, real-world experiences, and industry best practices. I have worked at Cotocus and regularly write about technology, travel, investing, health, product reviews, and digital marketing through my various platforms.

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