Could not load file or assembly System.Web.Extension

Last Reply on Jan 11, 2012 04:49 AM By Mudassar

Posted on Jan 10, 2012 04:53 AM

Server Error in '/' Application.

Configuration Error
Description: An error occurred during the processing of a configuration
file required to service this request. Please review the specific error
details below and modify your configuration file appropriately.

Parser Error Message: 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.

Source Error:

Line 36: <compilation debug="false">
Line 37: <assemblies>
Line 38: <add assembly="System.Web.Extensions,
Version=1.0.61025.0, Culture=neutral,
Line 39: </assemblies>
Line 40: </compilation>

There is a difference between the development machine and the
production server: On the development machine everything is on drive
C:. On the production server, the AJAX packages are installed on drive
C whereas the web applications run on a separate partition, drive F. I
am not sure if this is important.

I searched this forum, one guy mentioned that
Microsoft.Web.Extensions.dll and Microsoft.Web.Extensions.Design.dll
need to stay in the bin folder of the application. I don't think this
is true any more. That said, I still tried it, with no luck on the
production server.

Could you please help diagnose what might be wrong with the production
server side? Thanks.

I have even tried , loading System.Web.Extensions dll in bin folders 

and even installed ASPAJAXExtSetup.msi 

but nothing worked until nw



Thankz & Regards


Posted on Jan 10, 2012 05:19 AM

Just because other pages are not working you cannot say that IIS pool is fine.

Change IIS Pool to .Net 3.5

I agree, here is the link: