Could not load file or assembly 'System.Web.Pr

Question

hello this my config file

<?xml version="1.0"?>
<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
    <sectionGroup name="elmah">
      <section name="security" requirePermission="false" type="Elmah.SecuritySectionHandler, Elmah"/>
      <section name="errorLog" requirePermission="false" type="Elmah.ErrorLogSectionHandler, Elmah"/>
      <section name="errorMail" requirePermission="false" type="Elmah.ErrorMailSectionHandler, Elmah"/>
      <section name="errorFilter" requirePermission="false" type="Elmah.ErrorFilterSectionHandler, Elmah"/>
    </sectionGroup>
  </configSections>
  <connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=.\SQLEXPRESS;Initial Catalog=aspnet-MedicallexiconProject-2012615153521;Integrated Security=True" providerName="System.Data.SqlClient"/>
  </connectionStrings>
  <appSettings>
    <add key="webpages:Version" value="2.0.0.0"/>
    <add key="webpages:Enabled" value="true"/>
    <add key="PreserveLoginUrl" value="true"/>
    <add key="ClientValidationEnabled" value="true"/>
    <add key="UnobtrusiveJavaScriptEnabled" value="true"/>
  </appSettings>
  <system.web>
    <compilation targetFramework="4.0" debug="true"/>
    <authentication mode="Forms">
      <forms loginUrl="~/Account/Login" timeout="2880"/>
    </authentication>
    <pages>
      <namespaces>
        <add namespace="System.Web.Helpers"/>
        <add namespace="System.Web.Mvc"/>
        <add namespace="System.Web.Mvc.Ajax"/>
        <add namespace="System.Web.Mvc.Html"/>
        <add namespace="System.Web.Routing"/>
        <add namespace="System.Web.WebPages"/>
      </namespaces>
    </pages>
    <profile defaultProvider="DefaultProfileProvider">
      <providers>
        <add name="DefaultProfileProvider" type="System.Web.Providers.DefaultProfileProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/"/>
      </providers>
    </profile>
    <membership defaultProvider="DefaultMembershipProvider">
      <providers>
        <add name="DefaultMembershipProvider" type="System.Web.Providers.DefaultMembershipProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/"/>
      </providers>
    </membership>
    <roleManager defaultProvider="DefaultRoleProvider">
      <providers>
        <add name="DefaultRoleProvider" type="System.Web.Providers.DefaultRoleProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/"/>
      </providers>
    </roleManager>
    <sessionState mode="InProc" customProvider="DefaultSessionProvider">
      <providers>
        <add name="DefaultSessionProvider" type="System.Web.Providers.DefaultSessionStateProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/"/>
      </providers>
    </sessionState>
    <httpModules>
      <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah"/>
      <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah"/>
      <add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah"/>
    </httpModules>
  </system.web>
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules runAllManagedModulesForAllRequests="true">
      <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" preCondition="managedHandler"/>
      <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" preCondition="managedHandler"/>
      <add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" preCondition="managedHandler"/>
    </modules>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-4.0.0.0" newVersion="4.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089" culture="neutral"/>
        <bindingRedirect oldVersion="0.0.0.0-4.4.0.0" newVersion="4.4.0.0"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/>
  </entityFramework>
  <elmah>
    <security allowRemoteAccess="false"/>
  </elmah>
  <location path="elmah.axd" inheritInChildApplications="false">
    <system.web>
      <httpHandlers>
        <add verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah"/>
      </httpHandlers>
    </system.web>
    <system.webServer>
      <handlers>
        <add name="ELMAH" verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" preCondition="integratedMode"/>
      </handlers>
    </system.webServer>
  </location>
</configuration>

but when pulish on host rais this error Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: Could not load file or assembly 'System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

Source Error:

Line 44:     <membership defaultProvider="DefaultMembershipProvider">
Line 45:       <providers>
Line 46:         <add name="DefaultMembershipProvider" type="System.Web.Providers.DefaultMembershipProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/"/>
Line 47:       </providers>
Line 48:     </membership>

Answer 1

For me, I had upgraded the version of Web Providers with NuGet and this broke my app. I had to go into web.config and manually update all assembly references in the provider sections to 2.0.0.0 instead of 1.0.0.0 since the new version of the System.Web.Providers assembly was 2.0.0.0.

Answer 2

I think you should set Copy Local=true and ensure to use same version of .net framework.

Answer 3

In the Package Manager Console, I installed new packages as below and all was good in the world once again.

Install-Package Microsoft.AspNet.Providers
Install-Package Microsoft.AspNet.Providers.Core

Answer 4

Apparently you haven't deployed the System.Web.Providers assembly in your bin folder. Make sure it is marked with Copy Local=true?

Answer 5

Use this NuGet command to install your DLL automatically:

Install-Package Microsoft.AspNet.Providers.Core

For more information about Nuget Packages, read this and this one for a tutorial.