System. Web does not exist type or the namespace name script cannot find System. Web. Extensions. dll reference,

System. Web does not exist type or the namespace name script cannot find System. Web. Extensions. dll reference,

System. Web does not exist in the type or namespace name script/System. Web. Extensions. dll reference cannot be found

Just add reference... "Add reference →. net → System. web. entensions. dll. web. script. serialization; "OK...

System. Web. Extensions. dll reference not available

Select project property to change. Net version

This VS2010 Bug was encountered when the project compiled the Web Site after upgrading the code from VS2008 to VS2010. For details, see:

For [System. Web. Script. Services. ScriptService], we all know that it exists in System. Web. Extensions. dll. For this prompt, it seems to be a simple problem. Just add a reference to System. Web. Extensions. dll. That's what I think.

But the results are unexpected, and the problem persists...

What should we do? To solve Microsoft's problem, go to Google first and find that someone has encountered the same problem and reported it to ASP. NET Forums: Cannot find System. web. script. service namespace error after upgrading to Visual studio 2010, but the problem persists.

After research, we finally found a temporary solution to this problem.

Problem occurrence condition:

1. VS 2010 Web Site;

2. The target Framework for compilation is 3.5.

Solution:

Set System. web. extensions. dll is copied from C: \ Program Files \ Reference Assemblies \ Microsoft \ Framework \ v3.5 to C: \ Program Files \ Reference Assemblies \ Microsoft \ Framework \ v3.0, and VS2010 is restarted.

Summary:

The target Framework is v3.5, but VS2010 finds reference in GAC of v3.0. This is a Bug!

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