System.IO.FileNotFoundException: '无法加载文件或程序集 'Newtonsoft.Json，版本 = 12.0.0.0，

Question

This is the error that I get:

System.IO.FileNotFoundException: 'Could not load file or assembly 'Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed'. The system cannot find the file specified.'

This is what I have in cs project:

 <Reference Include="Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL"> <HintPath>..\\packages\\Newtonsoft.Json.12.0.3\\lib\\net45\\Newtonsoft.Json.dll</HintPath> </Reference>

The path seems to be correct.

I tried to find different solutions such as reinstalling the package to earlier version and modifying the app.config to this:

    <?xml version="1.0" encoding="utf-8"?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1"/>
    </startup>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-12.0.0.0" newVersion="12.0.3.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
</configuration>

Nothing has worked.

Answer 1

In my case, I have installed the V 12.0.0.3 by the Nuget package and I got the same error. According to my own experience . some of NewtonSoft versions are getting mad with some version of the Visual studio.

if you just need simple deserialize and serialize functionality, your problem will be solved if you reinstall the Newtonsoft current package from your solution and install the version 6.0.3

This version is so compatible with visual studio different versions.

Answer 2

Even though I had installed the Newtonsoft via "Manage NuGet Packages for Solution" I was still receiving this error. My fix was simple – I had to also add the "Newtonsoft.Json.dll" as a reference.

1.  Right-click "References" > Add > Reference > Browse > C:\Users\<username>\.nuget\packages\newtonsoft.json\12.0.3\lib\portable-net45+win8+wp8+wpa81\Newtonsoft.Json.dll > Click the "Add" button > Click "OK"
2.  I did a Build/Clean Solution (that step may not have been necessary)
3.  Build/Build Solution

Reran and the exception was gone.

Answer 3

This worked for me :

My issue : Recently updated newtonsoft to 13.0.0.0 and now VS is complaining about missing 9.0.0.0

1. Check the version of your Newtonsoft.JSON in References

2. Open Web.Config and change the bindingRedirect to the version in your reference

Answer 4

In your error it is stated that library version "12.0.0.0" was not found. In your config reference the version listed is "12.0.3"

The version mismatch could be the cause here.

When i encounter this issue it is usually after checking out code from source control and for some reason the references are missing. In this case it helped me to uninstall the nugets, check in, reinstall them and build (and check in again). Maybe this will work for you.

Answer 5

I had this exact same issue, i was working on a Web API and a self written DLL i wanted to debug.

Working on my DLL in the other project gave me this error.

But i followed these steps to finally resolve my issue:

1. Reinstall Newtonsoft.Json
2. Restart Visual Studio
3. Clean solution ( i believe this is the real solution )
4. Build/Rebuild solution

Answer 6

I suspect that when your project runs it isn't reading the .config that you expect because it is running from a different process. Try renaming your .config to match the calling process.

It might help to give more details about the type of VS project that you have.

Answer 7

This feels like one of those deja-vu issues for me - this particular time this exception was being thrown when my C# EXE file trying to call a web service. After trying to uninstall/reinstall/clean/rebuild/restart VStudio a dozen or so times I finally found a solution which was to just copy the files "Newtonsoft.Json.dll" and "Newtonsoft.Json.xml" to the output directory (alongside the EXE) - after doing this the error FINALLY went away. FWIW I realize this is very likely a hacky/ugly solution and not really solving the core issue - I'm just happy I can move on now.