Could not load file or assembly 'Newtonsoft.Json' or one of its dependencies. Manifest definition does not match the assembly reference

Things I've tried after searching:

1. in Web.Config put a binding on the old version:

   <dependentAssembly>
       <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
       <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.1.0" />
   </dependentAssembly>
   

2. Edit my .csproj file to make sure there is only one Newtonsoft reference

   <Reference Include="Newtonsoft.Json, Version=6.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
      <HintPath>..\packages\Newtonsoft.Json.6.0.1\lib\net45\Newtonsoft.Json.dll</HintPath>
      <SpecificVersion>False</SpecificVersion>
      <Private>True</Private>
   </Reference>
   

3. Search my computer for every Newtonsoft.Json.dll and delete every non 6.0.1 version and delete the contents of my temp folder

4. Repair/Reinstall the package in nuget manager console

It succeeds on building, but gets the error when going to the site.

EDIT

ok, so then I tried to reinstall like every nuget package, and it seems to have added back the 4.5 version of the newtonsoft.json.dll, but I'm getting the same error. My project's Target freamework is .NET 4.5.1 and here is the stack trace I'm getting now:

Server Error in '/' Application.

Could not load file or assembly Newtonsoft.Json or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.IO.FileLoadException: Could not load file or assembly Newtonsoft.Json or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Assembly Load Trace: The following information can be helpful to determine why the assembly Newtonsoft.Json could not be loaded.

=== Pre-bind state information ===
LOG: DisplayName = Newtonsoft.Json
(Partial)
WRN: Partial binding information was supplied for an assembly:
WRN: Assembly Name: Newtonsoft.Json | Domain ID: 2
WRN: A partial bind occurs when only part of the assembly display name is provided.
WRN: This might result in the binder loading an incorrect assembly.
WRN: It is recommended to provide a fully specified textual identity for the assembly,
WRN: that consists of the simple name, version, culture, and public key token.
WRN: See whitepaper http://go.microsoft.com/fwlink/?LinkId=109270 for more information and common solutions to this issue.
LOG: Appbase = file:///c:/users/user/documents/visual studio 2013/Projects/foo/bar/
LOG: Initial PrivatePath = c:\users\user\documents\visual studio 2013\Projects\foo\bar\bin
Calling assembly : (Unknown).
 ===
LOG: This bind starts in default load context.
LOG: Using application configuration file: c:\users\user\documents\visual studio 2013\Projects\foo\bar\web.config
LOG: Using host configuration file: C:\Users\user\Documents\IISExpress\config\aspnet.config
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///C:/Users/user/AppData/Local/Temp/1/Temporary ASP.NET Files/root/48686d37/9d7a6572/Newtonsoft.Json.DLL.
LOG: Attempting download of new URL file:///C:/Users/user/AppData/Local/Temp/1/Temporary ASP.NET Files/root/48686d37/9d7a6572/Newtonsoft.Json/Newtonsoft.Json.DLL.
LOG: Attempting download of new URL file:///c:/users/user/documents/visual studio 2013/Projects/foo/bar/bin/Newtonsoft.Json.DLL.
LOG: Using application configuration file: c:\users\user\documents\visual studio 2013\Projects\foo\bar\web.config
LOG: Using host configuration file: C:\Users\user\Documents\IISExpress\config\aspnet.config
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Redirect found in application configuration file: 4.5.0.0 redirected to 6.0.1.0.
LOG: Post-policy reference: Newtonsoft.Json, Version=6.0.1.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed
LOG: Attempting download of new URL file:///C:/Users/user/AppData/Local/Temp/1/Temporary ASP.NET Files/root/48686d37/9d7a6572/Newtonsoft.Json.DLL.
LOG: Attempting download of new URL file:///C:/Users/user/AppData/Local/Temp/1/Temporary ASP.NET Files/root/48686d37/9d7a6572/Newtonsoft.Json/Newtonsoft.Json.DLL.
LOG: Attempting download of new URL file:///c:/users/user/documents/visual studio 2013/Projects/foo/bar/bin/Newtonsoft.Json.DLL.
WRN: Comparing the assembly name resulted in the mismatch: Major Version
ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.

Stack Trace:

[FileLoadException: Could not load file or assembly 'Newtonsoft.Json' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]

[FileLoadException: Could not load file or assembly 'Newtonsoft.Json, Version=6.0.1.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
       System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +0
       System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +34
       System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +152
       System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +77
       System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +16
       System.Reflection.Assembly.Load(String assemblyString) +28
       System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +38

[ConfigurationErrorsException: Could not load file or assembly 'Newtonsoft.Json, Version=6.0.1.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
       System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +752
       System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +218
       System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +130
        System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +170
       System.Web.Compilation.BuildManager.GetPreStartInitMethodsFromReferencedAssemblies() +91
       System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +285
       System.Web.Compilation.BuildManager.ExecutePreAppStart() +153
       System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +516

[HttpException (0x80004005): Could not load file or assembly 'Newtonsoft.Json, Version=6.0.1.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
       System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9913572
       System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +101
       System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +254

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18408

To solve this, I ensured all my projects used the same version by running the following command and checking the results:

update-package Newtonsoft.Json -reinstall

And, lastly I removed the following from my web.config:

  <dependentAssembly>
    <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
  </dependentAssembly>

If you want to ensure all your Newtonsoft.Json packages are the same version, you can specify the version like so:

update-package Newtonsoft.Json -version 6.0.0 -reinstall

Note: To open the PMC in Visual Studio, click Tools -> Nuget Package Manager -> Package Manager Console. Thanks @Rose!

I am using Newtonsoft.Json v6.0.3, but this is what I had to do in my Web.config file:

<dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.5.0.0" newVersion="6.0.0.0" />
</dependentAssembly>

Note that even though I am using 6.0.3, I had to put in newVersion="6.0.0.0"

In my packages.config file I have:

<package id="Newtonsoft.Json" version="6.0.3" targetFramework="net45" />

I tried the following after having already ensured that my computer had the same version in all locations and that my projects were all pointing to the same reference path. I had also made sure that the binding of the old version was their and bound to the current version of dll that I had.

I work in an environment with a strict framework and the framework team often upset the versioning with the different dll's.

How I fixed this issue was to run the package manager console within visual studio (2013). From there I ran the following command:

update-package Newtonsoft.Json -reinstall

followed by

update-package Newtonsoft.Json

This went through and updated all of my config files and relevant project files. Forcing them all to the same version of the dll. Which was initially version 4.5 before updating again to get the latest.

I had the same error message and, like you mentioned, it was due to different versions of the Newtonsoft.Json.dll being referenced.

Some projects in my MVC solution used the NuGet package for version 4 of that dll.

I then added a NuGet package (for Salesforce in my case) that brought Newtonsoft.Json version 6 with it as a dependency to one of the projects. That was what triggered the problem for me.

To clean things up, I used the Updates section in the NuGet Package Manager for the solution (off Tools menu or solution right-click) to update the Json.Net package throughout the solution so it was the same version for all projects.

After that I just checked the App Config files to ensure any binding redirect lines were going to my chosen version as below.

<bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />