I am trying to use JavaScriptSerializer in my application.
I initially received
Cannot find JavaScriptSerializer
and I solved it by adding:
using System.Web.Script.Serialization;
But then the sub-keyword Script is underlined with a blue line:
The type or namespace ‘Script’ does not exist in the namespace
‘System.Web’ (are you missing an assembly reference?)
So I added to the project a reference to:
C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\System.Web.Extensions.dll
That didn’t help. I am still receiving the same blue underline with same error. The reference is marked with an exclamation mark yellow warning:

I tried the suggested solutions on this thread, but as @user781490 indicated, they didn’t help in my situation.
Any idea how to resolve this?
I found this MSDN forum post which suggests two solutions to your problem.
First solution (not recommended):
Second solution (Use a different class / library):
The user who had posted the question claimed that
Uri.EscapeUriStringand How to: Serialize and Deserialize JSON Data helped him replicate the behavior ofJavaScriptSerializer.You could also try to use Json.Net. It’s a third party library and pretty powerful.