'Invalid static method invocation syntax' error in Microsoft.Windows.SDK.BuildTools.MSIX.Packaging.targets

[ZarehD]

Describe the bug

Error:

MSB4186: Invalid static method invocation syntax: "[System.String]::Copy(Inter-Italic-VariableFont_opsz,wght.ttf).EndsWith('.deps.json')". Method 'System.String.Copy' not found. Static method invocation should be of the form: $([FullTypeName]::Method()), e.g. $([System.IO.Path]::Combine(`a`, `b`)). Check that all parameters are defined, are of the correct type, and are specified in the right order.

File:

C:\Users\<user>\.nuget\packages\microsoft.windows.sdk.buildtools.msix\1.7.20250829.1\build\Microsoft.Windows.SDK.BuildTools.MSIX.Packaging.targets

Faulting Code:
Line 4336
Mmissing single-quotes around %(FileName)%(Extension) parameter in [System.String]::Copy call.

<_PublishDepsJsonFiles Include="@(_PublishPackagingOutputs)"
  Condition="'@(_PublishPackagingOutputs)' != '' and $([System.String]::Copy(%(FileName)%(Extension)).EndsWith('.deps.json'))" />

Fix:
Add single qutes around the %(FileName)%(Extension) parameter:

... and $([System.String]::Copy('%(FileName)%(Extension)').EndsWith('.deps.json'))

Version Info:
OS: Win11 Pro, 25H2 (OS Build: 26200.8117)
IDE: VS2026 v18.4.3
Project: .NET-10 MAUI Windows app

<PropertyGroup>
  <WindowsPackageType>MSIX</WindowsPackageType>
</PropertyGroup>

Steps to reproduce the bug

1. Create a default MAUI packaged (MSIX) project from template.
2. Build the project.

Expected behavior

MAUI project builds successfully without errors.

Screenshots

No response

NuGet package version

1.7.20250829.1 --> installed by VS2026 IDE

Packaging type

Packaged (MSIX)

Windows version

No response

IDE

No response

Additional context

The MSIX Packaging Tools were installed as part of the VS 2026 .NET Desktop Development workload. They were not installed separately as a Nuget package.