Microsoft.VisualStudio.JavaScript.SDK FileNotFoundException System.Text.Json, Version=9.0.0.11

[DaleyKD]

Describe the bug

Can't build an .esproj using Microsoft.VisualStudio.JavaScript.SDK/1.0.4338480. Results in:

The "GeneratePackageJsonProps" task failed unexpectedly.
System.IO.FileNotFoundException: Could not load file or assembly 'System.Text.Json, Version=9.0.0.11, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The system cannot find the file specified.
File name: 'System.Text.Json, Version=9.0.0.11, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
   at Microsoft.VisualStudio.JavaScript.Tasks.GeneratePackageJsonProps.Execute()
   at Microsoft.Build.BackEnd.TaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

To Reproduce

Exceptions (if any)

Further technical details

PS C:\> dotnet --info
.NET SDK:
 Version:           10.0.102
 Commit:            4452502459
 Workload version:  10.0.100-manifests.6d969a7e
 MSBuild version:   18.0.7+445250245

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.26200
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\10.0.102\

.NET workloads installed:
There are no installed workloads to display.
Configured to use workload sets when installing new manifests.
No workload sets are installed. Run "dotnet workload restore" to install a workload set.

Host:
  Version:      10.0.2
  Architecture: x64
  Commit:       4452502459

.NET SDKs installed:
  3.1.426 [C:\Program Files\dotnet\sdk]
  6.0.428 [C:\Program Files\dotnet\sdk]
  8.0.417 [C:\Program Files\dotnet\sdk]
  9.0.310 [C:\Program Files\dotnet\sdk]
  10.0.102 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.23 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 9.0.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 10.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.23 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 9.0.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 10.0.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 8.0.23 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 9.0.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 10.0.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
  x86   [C:\Program Files (x86)\dotnet]
    registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download

• The IDE (VS / VS Code/ VS4Mac) you're running on, and its version: Visual Studio 2026 18.2.1

[DaleyKD]

I opened another project, manually added System.Text.Json 9.0.11 so that it was part of my nuget cache, closed Visual Studio and reopened, and it finally built. But I've found that it's hit or miss.

[bernik1980]

Having the same issue after upgrading to Microsoft.VisualStudio.JavaScript.Sdk/1.0.4671869

Restarting Vistual Studio did not help.

After downgrading back to Microsoft.VisualStudio.JavaScript.Sdk/1.0.4338480 and restarting, I could compile again.

[DaleyKD]

Everything was working great after I manually added System.Text.Json 9.0.11. Until just a minute ago. I restarted the computer and that didn't fix it. I didn't change anything that should have affected this.

[jomonty]

Also having this issue. Can confirm 1.0.4338480 (~ 2 months ago) working fine. 1.0.4622013 and 1.0.4671869 released in the last week are causing issues.

[fforjanAVEVA]

we're having the same issue on our build machine, note that we are still with Visual Studio 2022 on our build machines and not upgrade to 2026 yet

[Dzoge]

Has this been triaged by MS?

[joj]

I'll take a look. I don't think anything changed on the SDK, but if reverting helps then that's where I will start.

[joj]

I'll take a look. I don't think anything changed on the SDK, but if reverting helps then that's where I will start.

[fforjanAVEVA]

@joj any update ?

[fforjanAVEVA]

@joj it is still failing, even with the latest version