erro na pág (<customErrors>)

um código que axei na net está dando o seguinte erro:

Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.

Details: To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".

<!-- Web.Config Configuration File -->

<configuration>
 <system.web>
 <customErrors mode="Off"/>
 </system.web>
</configuration>

Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's <customErrors> configuration tag to point to a custom error page URL.

<!-- Web.Config Configuration File -->

<configuration>
 <system.web>
 <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>
 </system.web>
</configuration>

 

 

 

mas se Add a tag <customErrors> que pede ocorre um erro na pag, é o lugar que estou colocando que está errado, se sim, onde no código eu deveria colocar... o codigo da pag está abaixo:

 

<?xml version="1.0"?>

<!-- Note: As an alternative to hand editing this file you can use the web admin tool to configure settings for your application. Use the Website->Asp.Net Configuration option in Visual Studio. A full list of settings and comments can be found in machine.config.comments usually located in \Windows\Microsoft.Net\Framework\v2.x\Config -->

<configuration>
<configSections>
	<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
 <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
 <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
 <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
 <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/>
 <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
 <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
 <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/></sectionGroup></sectionGroup></sectionGroup>
</configSections>
<appSettings>
 <add key="ConnectionString" value="Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Inetpub\wwwroot\Classmates\App_Data\ClassmatesDemoDb.mdf;Integrated Security=True;User Instance=True"/>
</appSettings>
<connectionStrings>
	<add name="ConnectionString1" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Inetpub\wwwroot\Classmates\App_Data\ClassmatesDemoDb.mdf;Integrated Security=True;User Instance=True"/>
	<add name="ConnectionString2" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Inetpub\wwwroot\Classmates\App_Data\ClassmatesDemoDb.mdf;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/>
</connectionStrings>

<system.web>

<!--
Set compilation debug="true" to insert debugging
symbols into the compiled page. Because this
affects performance, set this value to true only
during development.
-->

	<compilation debug="true">
 <assemblies>
 <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
 <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
 <add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
 <add assembly="System.Web.Extensions.Design, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
 <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/></assemblies>
	</compilation>
	<!--
 The <authentication> section enables configuration
 of the security authentication mode used by
 ASP.NET to identify an incoming user.
 -->
	<authentication mode="Windows"/>
	<!--
 The <customErrors> section enables configuration
 of what to do if/when an unhandled error occurs
 during the execution of a request. Specifically,
 it enables developers to configure html error pages
 to be displayed in place of a error stack trace.

 <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
 <error statusCode="403" redirect="NoAccess.htm" />
 <error statusCode="404" redirect="FileNotFound.htm" />
 </customErrors>
 -->
	<pages>
 <controls>
 <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 </controls>
	</pages>
	<httpHandlers>
 <remove verb="*" path="*.asmx"/>
 <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
	</httpHandlers>
	<httpModules>
 <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
	</httpModules>
</system.web>

<system.codedom>

	<compilers>
 <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
 <providerOption name="CompilerVersion" value="v3.5"/>
 <providerOption name="WarnAsError" value="false"/>
 </compiler>
 <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" warningLevel="4" type="Microsoft.VisualBasic.VBCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
 <providerOption name="CompilerVersion" value="v3.5"/>
 <providerOption name="OptionInfer" value="true"/>
 <providerOption name="WarnAsError" value="false"/>
 </compiler>
	</compilers>
</system.codedom>

<!--
The system.webServer section is required for running ASP.NET AJAX under Internet
Information Services 7.0. It is not necessary for previous version of IIS.
-->
<system.webServer>

	<validation validateIntegratedModeConfiguration="false"/>
	<modules>
 <remove name="ScriptModule"/>
 <add name="ScriptModule" preCondition="managedHandler" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
	</modules>
	<handlers>
 <remove name="WebServiceHandlerFactory-Integrated"/>
 <remove name="ScriptHandlerFactory"/>
 <remove name="ScriptHandlerFactoryAppServices"/>
 <remove name="ScriptResource"/>
 <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
 <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
	</handlers>
</system.webServer>
<runtime>
	<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>
 <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
 </dependentAssembly>
 <dependentAssembly>
 <assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35"/>
 <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
 </dependentAssembly>
	</assemblyBinding>
</runtime>
</configuration>