Sharepoint LINQ The type or namespace name 'Linq' does not exist in the namespace 'System'

Question

I have sharepoint Foundation 2010 installed in my Win7 Home premium 64 bit laptop.

I used layouts folder to copy my aspx pages which has two imports using using System.Linq;,Microsoft.SharePoint.Linq;I am getting this error

The type or namespace name 'Linq' does not exist in the namespace 'System' (are you missing an assembly reference?) But even adding the following lines as suggested in many forums

I changed the web.xml file available under C:\inetpub\wwwroot\wss\VirtualDirectories\80 to add the following content

    <add assembly="Microsoft.Web.CommandUI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
    <add assembly="Microsoft.SharePoint.Search, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />


    <add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="System.Data.Linq, 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.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Web.Extensions.Design, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Web.Extensions.Design, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>

  </assemblies>

and this before </configuration>

<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>

Please Guide

Stefan Stefan · Accepted Answer · 2012-05-21T08:54:20

I checked this on my work box: All you need to include in the web.config is the System.Core assembly and a compiler element with the CompilerVersion set to "v3.5".

This goes into Configuration/system.web/compilation:

<assemblies>
  <add assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
  <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
  <add assembly="Microsoft.Web.CommandUI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
  <add assembly="Microsoft.SharePoint.Search, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
  <add assembly="Microsoft.Office.Access.Server.UI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
  <add assembly="Microsoft.SharePoint.Publishing, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />
  <add assembly="Microsoft.Office.Server.Search, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" />

  <!-- Additional Assembly -->
  <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
</assemblies>

This goes into /Configuration/:

<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>
  </compilers>
</system.codedom>

The assemblies System.Data.Linq and System.Data.Linq are not required.

Sharepoint LINQ The type or namespace name 'Linq' does not exist in the namespace 'System'

2 Answers