Q:
I face the following problem only when i tried my web site from the production server.
locally every thing goes okay.
Assembly Load Trace: The following information can be helpful to
determine why the assembly ‘Telerik.Web.UI, Version=2011.2.712.35,
Culture=neutral, PublicKeyToken=121fae78165ba3d4’ could not be loaded.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].
Note: If i paste the Telerik dll in the bin folder .the problem is fixed.
but i wanna to know the reason , and any way to fix this problem without copy and paste the dll in the bin folder.
If I understand your question well, try to include this file as a reference inside your project, so every time you make a deployment, it will by default include it inside the bin folder.
this is to avoid copying the file every time you deploy.
let me know if this fits your problem or not.
Update: as per your comment, kindly check my attached image, and follow my instructions below.

1- Open “references” and select your “telerik” Dll
2- Right click over it and select “Properties”, or simply press “F4”.
3- check that the option says “Copy Local” is True, if not,then change it.
4- make another deployment, now it suppose to copy your desired Dll in the bin folder.
5- draw a big smile, the problem is gone!!. 🙂
let me know if this address your problem correctly, thanks