MVC 4 website load shows HTTP Error 500.19

Question

I created a new ASP.NET MVC 4 application based on Internet application template, I could succesfully run it and authenticate user from within VS 2012 Express.

Then published it to a folder in wwwroot, then in IIS 7.5 manager created a virtual directory pointing to that folder, and converted it to an application using a separate 4.0 integrated pool.

When I tried to browse the application from within the IIS manager I get the next error:

HTTP Error 500.19 - Internal Server Error, The requested page cannot be accessed because the related configuration data for the page is invalid.

Config Error: Cannot add duplicate collection entry of type 'add' with unique key attribute 'name' set to 'ExtensionlessUrlHandler-Integrated-4.0'

Config source:

56:       <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0"/>
57:       <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" resourceType="Unspecified" requireAccess="Script" preCondition="integratedMode,runtimeVersionv4.0" />   
58:     </handlers>

searched here,I found the corresponding answer:

Resolution 1

Delete the malformed XML element from the ApplicationHost.config file or from the Web.config file.

My web.config file is as below:

    <?xml version="1.0"?>
    <configuration>
      <configSections>
        <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
      </configSections>
      <connectionStrings>
        <add name="DefaultConnection" connectionString="Data Source=(LocalDb)\v11.0;Initial Catalog=aspnet-digixMVC4-20120915233326;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnet-digixMVC4-20120915233326.mdf" providerName="System.Data.SqlClient"/>
      </connectionStrings>
      <appSettings>
        <add key="webpages:Version" value="2.0.0.0"/>
        <add key="webpages:Enabled" value="false"/>
        <add key="PreserveLoginUrl" value="true"/>
        <add key="ClientValidationEnabled" value="true"/>
        <add key="UnobtrusiveJavaScriptEnabled" value="true"/>
      </appSettings>

      <!--
        The following attributes can be set on the <httpRuntime> tag.
          <system.Web>
            <httpRuntime targetFramework="4.5"/>
          </system.Web>
      -->
      <system.web>
        <compilation targetFramework="4.5"/>
        <httpRuntime/>
        <authentication mode="Forms">
          <forms loginUrl="~/Account/Login" timeout="2880"/>
        </authentication>
        <pages controlRenderingCompatibilityVersion="4.0">
          <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.Optimization"/>
            <add namespace="System.Web.Routing"/>
            <add namespace="System.Web.WebPages"/>
          </namespaces>
        </pages>
      </system.web>
      <system.webServer>
        <validation validateIntegratedModeConfiguration="false"/>
        <handlers>
          <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit"/>
          <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit"/>
          <remove name="ExtensionlessUrlHandler-Integrated-4.0"/>
          <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0"/>
          <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0"/>
<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0"/>
          <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" resourceType="Unspecified" requireAccess="Script" preCondition="integratedMode,runtimeVersionv4.0" />      
        </handlers>
      </system.webServer>
      <runtime>
        <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
          <dependentAssembly>
            <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364g85"/>
            <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0"/>
          </dependentAssembly>
          <dependentAssembly>
            <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364g85"/>
            <bindingRedirect oldVersion="1.0.0.0-4.0.0.0" newVersion="4.0.0.0"/>
          </dependentAssembly>
          <dependentAssembly>
            <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364g85"/>
            <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0"/>
          </dependentAssembly>
        </assemblyBinding>
      </runtime>
      <entityFramework>
        <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/>
      </entityFramework>
    </configuration>

As I am a poorly skilled developer in MVC 4, I would ask if someone could find out the malformed xml element in the file above.

score 8 · Answer 1 · answered Sep 30 '14 at 04:22

This is true for ASP.NET WebAPI 5.2 too..

I had

  <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
  <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />

Which I changed to

  <add name="ExtensionlessUrlHandler-Integrated-4.0a" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
  <add name="ExtensionlessUrlHandler-Integrated-4.0b" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />

Thats it.. It worked.

Isn't it the same handler? Why need to add it twice with different name? — Hoàng Long, Jan 14 '16 at 06:10

score 6 · Answer 2 · edited Jan 22 '13 at 12:30

6

you have the same name in twice. the name must be unique.

current config

<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0"/>

<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" resourceType="Unspecified" requireAccess="Script" preCondition="integratedMode,runtimeVersionv4.0" />

change to

<add name="ExtensionlessUrlHandler-Integrated-4.0a" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0"/>

<add name="ExtensionlessUrlHandler-Integrated-4.0b" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" resourceType="Unspecified" requireAccess="Script" preCondition="integratedMode,runtimeVersionv4.0" />

edited Jan 22 '13 at 12:30

J. Steen

15,470
15
56
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answered Jan 22 '13 at 12:09

kieron

61
1
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1

I don't see the same name twice, there is different postfix _32bit or _64bit. Is it this postfix somehow magic? – Tomas Kubes Jan 29 '15 at 10:09
The issue occurs for me, as well. I too have the _32bit/_64bit postfix, however modifying the strings in any way will resolve the issue, just as long as both strings are modified. The two can have the same exact body but keep the original _32bit/_64bit postfix and it will still work, which tells me it is *not* a magic prefix. I suspect it's checking for matches amongst other projects in the solution / on the server. That, or something weird is going on in IIS. – 16807 Aug 20 '15 at 19:16
Figured it out after reading this: http://stackoverflow.com/questions/26271958/what-does-extensionlessurlhandler-do-in-an-mvc-application. The order of the add/remove tags apparently matters. I was adding the ExtensionlessUrlHandlers before removing the existing defaults provided by IIS. The defaults had the same name as the handlers I added, hence the error. – 16807 Aug 20 '15 at 19:46

score 1 · Answer 3 · 2017-04-13T20:44:19.007

1

I experienced a similar problem to this.

what worked for me was to remove, then re-add the handler:

My guess is that if by default this is enabled in the IIS Server already, it may trigger this error.

I am using IIS 10, MVC 5, .NET Framework 4.6.1

Hope this helps :-)

edited Apr 13 '17 at 20:44

answered Apr 13 '17 at 20:37

MVC 4 website load shows HTTP Error 500.19

3 Answers3