How to resolve error "CS0234: The type or namespace name 'Optimization' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)"

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I have created asp .net web form application in VS 2012 and run the default.aspx page.
I got following runtime error

XML

Server Error in '/' Application.
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0234: The type or namespace name 'Optimization' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)

Source Error:


Line 17:     <pages>
Line 18:       <namespaces>
Line 19:         <add namespace="System.Web.Optimization" />
Line 20:       </namespaces>
Line 21:       <controls>


Source File: .../WebApp2/Web.config    Line: 19


Show Detailed Compiler Output:

Show Complete Compilation Source:


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.17929

As per show solution by googling this error, I have tried to resolved by copy System.Web.Optimization.dll from package folder to bin folder but issue not resolved.
Please give the solution.

Posted 30-Jun-15 22:46pm

Makarand Borawake

Updated 19-Jul-15 21:09pm

v3

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F-ES Sitecore 1-Jul-15 4:59am

Have you added a reference to the optimisation assembly in your project?

Makarand Borawake 1-Jul-15 5:00am

Yes I have added reference.

1 solution

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Abhinav S · Answer 1 · 2015-06-30T23:04:00

Solution 1

Try installing Microsoft.AspNet.Web.Optimization via nuget (as it is not installed by the framework).
Try install-package Microsoft.AspNet.Web.Optimization in the nuget prompt.

Posted 30-Jun-15 23:04pm

Abhinav S

Comments

Makarand Borawake 1-Jul-15 5:16am

Thanks!!
I tried above solution, but gave same error.

Stevey T 23-Jul-20 13:14pm

So I am having the same similar issue. I cloned my tfs project and ran it locally and it gives Me the same error/issue. Originally I wrote created my project locally and then placed it in a tfs project. It worked locally but now that I am using tfs its giving namespace errors for Optimization, BundleCollection, ASPNet,ScriptBundle and so on. How do I resolve this issue?