System.Web.Extensions, Version=1.0.61025.0

[[e-mail]]

This one had me going for 3 days.
"Could not load file or assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified."  This message would show up in the Visual Studio IDE in design windows with any Telerik control.

Hopefully, my experiences will save others some time.

The root-cause of this messagewas that the system was looking for .net 2 dlls when the project is .net35.

Telerik's support kept on advising me to make sure my project was actually .net 3.5.  It was. My project is three tier, and all modules at each of the three levels was set for a 3.5 build.

The problem persisted.  The Telerik.web.ui.dll in the bin folder was removed and the references added again, ensuring that they were from the Telerik bin35 folder.
The tools were removed and re-added, again ensuring that they were from the Telerik bin35 folder.  All would work correctly for a while (say an hour) and then the Telerik.web.ui.dll in the bin folder would mysteriously become the .net 2 version.  The refresh file and tools would remain pointing at the bin 35 version.

All very confusing.

The issue causing this problem was that in my middle tier (business logic) I had included a helper class to support the Telerik TreeView control, and had a reference in there to the Telerik.web.ui.dll.  That reference was to the wrong folder (bin as opposed to bin 35).

Every time I built the web-site the complier would find this reference at the lower level and silently replace the Telerik.Web.ui.dll at the higher level.  No warnings, no questions, just replaced the dll. Sneeky, huh!


 

[Kevin Babcock]

Hello RDavid,

It is definitely important to ensure your project is using the correct assemblies. Good catch! I'm glad you were able to resolve your issue.

Thanks for sharing the solution.

Regards,
Kevin Babcock

[mAhdi]

hi
i have same problem
when i ran it on my dev machine it had no error but when i upload it on server this error occurs!
then i deleted refrecne to Telerik.Web.UI in my project,replaced DLLs from bin35 folder and created the refrecne again, compiled and uploaded these to server, but error still exists, i use VS2008 and XPSP3 and .NET3.5 SP1 and Telerik3.5(2009.1.311.35), Note that my project was in .NET2 and VS2005 and i upgraded it mybe some settings from .NET2 still exists in my web.config, my web.config is here:

<?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 xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <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>
  <system.web>
    <customErrors mode="Off" />
    <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.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
        <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
        <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" />
        <add assembly="System.Drawing.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
      </assemblies>
    </compilation>
    <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" validate="false" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
      <add path="Telerik.Web.UI.WebResource.axd" type="Telerik.Web.UI.WebResource" verb="*" 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>
  <connectionStrings>
    <remove name="LocalSqlServer" />
    <add name="hConnectionString" connectionString="something"
      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.
        -->
    <!--
            The <authentication> section enables configuration
            of the security authentication mode used by
            ASP.NET to identify an incoming user.
        -->
    <authentication mode="Forms">
      <forms loginUrl="login.aspx" cookieless="UseCookies" domain="thisdomain.com" defaultUrl="Default.aspx" name=".MAHDIFORMSAUTH" path="/" slidingExpiration="false" />
    </authentication>
    <!--
            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>
        -->
  </system.web>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CSharp.CSharpCodeProvider,System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" warningLevel="4">
        <providerOption name="CompilerVersion" value="v3.5" />
        <providerOption name="WarnAsError" value="false" />
      </compiler>
    </compilers>
  </system.codedom>
  <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" verb="GET,HEAD" path="ScriptResource.axd" preCondition="integratedMode" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
      <add name="Telerik_Web_UI_WebResource_axd" verb="*" preCondition="integratedMode" path="Telerik.Web.UI.WebResource.axd" type="Telerik.Web.UI.WebResource" />
    </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>

[[e-mail]]

Hi mAhdi,

You posted you comments at the bottom of one of my posts so I am not sure if any of the good folks at Telerik Support will see it and respond.  I find that they provide very, very good support and raising a support request will normally get you the solution.

Anyway, I don't think that your problem is the same as mine was, as my problem was occuring on my development machine and was due to my stupidity (aren't most problems).

The things that I would check in your situation are:

1) Is the Telerik.DLL held in you Bin folder or is it in GAC (or a confusing mixture of both).  If you are holding it in your GAC, check that the production server is also using the same Telerik DLL.

2) In my web.config file I have the following under Assembles:

<

 

add assembly="Telerik.Web.Design, Version=2009.1.311.35, Culture=neutral, PublicKeyToken=121FAE78165BA3D4"/>

 

I am not sure what difference this will make, but it is worth a try.

Good luck

Richard

[Hari]

I have the exact same problem, except few differences:

1. It is compiling perfectly in my workstation, but the build fails in the build server (teamcity). The build server has both 1.0.61025.0 & 3.5.0.0 versions of System.Web.Extensions dll in GAC.

2. We use 2009.1.420.35 version of telerik.web.ui.dll and this project is a brand new one developed in .NET 3.5/VS 2008. It doesn't have any indirect references to the older version of telerik dll's.

Any clues, why this would happen?

Thanks,

Hari Krishnan.