I have a web.config file in a parent directory that applies to files in that directory.  Then I have another web.config in a directory within the parent directory for it's files.  It was running okay until our last release and now the aspx files in the subdirectory give me a "Could not load the 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." error.  The web.config in the parent directory has a reference to System.Web.Extensions in <sectiongroup> and <assemblies>, but the other web.config does not.  If I copy those pieces from the other web.config into this one, I get "Section or group name 'system.web.extensions' is already defined. Updates to this may only occur at the configuration level where it is defined."  What can I do to fix this?

Friend, try this

http://forums.asp.net/t/1135367.aspx

Hope it helped you. Good luck!

Thanks, I looked at the link, but mine is a different problem.  The parent site is using the System.Web.Extensions piece and works fine.  The child site does not use the System.Web.Extensions piece.  It seems to me to be an inheritance issue, so I tried using <remove> in the assemblies section of the child web.config.  The error went away when I used it on my development server, but when I do it on my production server, I still get the error.  I also tried using <location path="." inheritInChildApplications="false"> around system.web in the parent web.config and that did not work.

Any ideas?

using remove to unload the assembly is definitely the right way to do this.  If it works on  your dev server but not your production server, the change is working.  Are you sure you copied the new web.config over? 

Just checked it again - I'm positive the code is in there.  Don't know if it will help, but here's the error text:

Exception Details: System.IO.FileNotFoundException: 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:

WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

I have another clue that may help solve this puzzle.  I remembered that with this release we are now using LINQ in the parent directory.  I noticed that the parent web.config has 2 versions of the system.web.extensions assembly.  Here's the assembly portion of the file:

<assemblies>
    <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Data.DataSetExtensions, 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.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
    <add assembly="System.Transactions, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
 </assemblies>

However, when I take out either one of these, I get an error on the using statement that looks for LINQ.

Help, anyone????

Hi webbertc,

The “'System.Web.Extensions” is the Strong Named assembly that should be installed in GAC, the file not found issue should not caused by the relative path problem of the sub directory. In my opinion, the problem is the AJAX 1.0 extension is not installed on the server.

To solve this issue, we can remove the “1.0.61025.0” version “System.Web.Extensions” assembly from the “assemblies” section. As you said, after doing that, the LINQ assembly not found issue appears. For this issue, I would recommend checking if .NET Framework 3.5 installed on the Server.