无法加载文件或程序集'System.Web.Helpers'

Question

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

Server Error in '/api' Application. 

Could not load file or assembly 'System.Web.Helpers' 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 'System.Web.Helpers' 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 'System.Web.Helpers' could not be loaded. 


=== Pre-bind state information === 
LOG: DisplayName = System.Web.Helpers 
(Partial) 
WRN: Partial binding information was supplied for an assembly: 
WRN: Assembly Name: System.Web.Helpers | Domain ID: 3 
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:/source/TDMS/TDMS.WebServices/ 
LOG: Initial PrivatePath = C:\source\TDMS\TDMS.WebServices\bin 
Calling assembly : (Unknown). 
=== 
LOG: This bind starts in default load context. 
LOG: Using application configuration file: C:\source\TDMS\TDMS.WebServices\web.config 
LOG: Using host configuration file: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet.config 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\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:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/api/8f8ef96b/51bdcfc3/System.Web.Helpers.DLL. 
LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/api/8f8ef96b/51bdcfc3/System.Web.Helpers/System.Web.Helpers.DLL. 
LOG: Attempting download of new URL file:///C:/source/TDMS/TDMS.WebServices/bin/System.Web.Helpers.DLL. 
LOG: Using application configuration file: C:\source\TDMS\TDMS.WebServices\web.config 
LOG: Using host configuration file: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet.config 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config. 
LOG: Redirect found in application configuration file: 1.0.0.0 redirected to 3.0.0.0. 
LOG: Post-policy reference: System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35 
LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/api/8f8ef96b/51bdcfc3/System.Web.Helpers.DLL. 
LOG: Attempting download of new URL file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/Temporary ASP.NET Files/api/8f8ef96b/51bdcfc3/System.Web.Helpers/System.Web.Helpers.DLL. 
LOG: Attempting download of new URL file:///C:/source/TDMS/TDMS.WebServices/bin/System.Web.Helpers.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 'System.Web.Helpers' 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 'System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 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.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +234 
    System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +108 
    System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +25 
    System.Reflection.Assembly.Load(String assemblyString) +34 
    System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +49 

[ConfigurationErrorsException: Could not load file or assembly 'System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 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) +772 
    System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +259 
    System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +163 
    System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +230 
    System.Web.Compilation.BuildManager.GetPreStartInitMethodsFromReferencedAssemblies() +76 
    System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +139 
    System.Web.Compilation.BuildManager.ExecutePreAppStart() +176 
    System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +882 

[HttpException (0x80004005): Could not load file or assembly 'System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 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) +579 
    System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +112 
    System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +712 

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.6.1055.0 

这发生在TDMS.WebServices项目中，该项目是.net 4.5 Web API 2.0。我们也有一个MVC5项目。

从bin文件夹中删除.dll并再次编译修复它。重建会将DLL带回并删除它。

有些东西是注入system.web.helpers.dll到bin文件夹，我不知道是什么造成它，但我怀疑它可能与MVC项目有关的System.Web.Helpers

更新：

这是新的错误我重做引用后得到：

Could not load file or assembly 'System.Web.Helpers' 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 'System.Web.Helpers' 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 'System.Web.Helpers' could not be loaded. 


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]. 

Stack Trace: 


[FileLoadException: Could not load file or assembly 'System.Web.Helpers' 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 'System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 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.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +234 
    System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +108 
    System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +25 
    System.Reflection.Assembly.Load(String assemblyString) +34 
    System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +49 

[ConfigurationErrorsException: Could not load file or assembly 'System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 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) +772 
    System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +259 
    System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +163 
    System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +230 
    System.Web.Compilation.BuildManager.GetPreStartInitMethodsFromReferencedAssemblies() +76 
    System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +139 
    System.Web.Compilation.BuildManager.ExecutePreAppStart() +176 
    System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +882 

[HttpException (0x80004005): Could not load file or assembly 'System.Web.Helpers, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 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) +579 
    System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +112 
    System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +712 

Answer 1

你说得对，它正在从MVC简称。 System.Web.Helpers通常是您在NuGet上可以找到的包Microsoft.AspNet.WebPages的一部分。在某些运行时环境中，它安装在GAC中并因此公开可用。

从控制台的NuGet，运行

Update-Package Microsoft.AspNet.WebPages 

请确保您有在web.config中重定向：

<dependentAssembly> 
    <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" /> 
    <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
</dependentAssembly> 

Answer 2

Add the reference of System.Web.Helpers.dll file to your project, 

and add below setting in web.config file 

<dependentAssembly> 
    <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" /> 
    <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" /> 
</dependentAssembly>