Hi Jay P.,

It seems to me that you have more than one Telerik.Web.UI assembly added to your GAC, or you have one version in GAC and another in your project. Please, make sure that you are using only one Telerik.Web.UI assembly in your project. You can either remove the old assembly versions from GAC (manually or by uninstalling older versions of RadControls for ASP.NET AJAX / Prometheus), or use strong name (fully qualified) assembly reference in your web application's web.config.

Hope this helps.


Sincerely yours,
Dimo
the Telerik team

Jay,
I am running into the same problem with my upgrade also. How or did you solve your problem?

Thanks Judie

Also check this:

http://www.telerik.com/help/aspnet-ajax/installupgrading.html

Greetings:

Forgive me if this has already been solved; but I cannot find it anywhere on the forum.

I recently upgraded from RadControls AJAX Q1 2008 to Q2 2008.

All of my development to that point works OK, however, the following error that is appearing at design time:

Warning 1 Generation of designer file failed: Unable to create type 'telerik:RadGrid'. 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. 

This error is shown anytime there is a Telerik control being added to a page.
Looking in the web.config there is no reference to anything with that version, so I don't know who is referencing it.  The following redirection is in the web.config...

<

runtime>

<

assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">

<

dependentAssembly>

<

assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>

<

bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>

</

dependentAssembly>

<

dependentAssembly>

<

assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35"/>

<

bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>

</

dependentAssembly>

</

assemblyBinding>

</

runtime>

Without the above redirection, the runtime will fail.  Still nothing seems to be helping with the design time issue.

Dot.NET 3.5 is installed.

Once this error is shown, then the code behind page cannot see any new tags being added to the aspx page.

I have tried for 3 days to find the answer on this site and others; but now I must surrender and post this request for help.

Please advise if you have some idea how to resolve this.

Thanks,

Robb Murdock

PROBLEM SOLVED ???

Greetings:

Somehow I have solved or circumvented the problem.

Please tell me if this makes any sense.

I discovered that Telerik 2008 Q2 install directory has two BIN directories:

C:\Program Files\telerik\RadControls for ASPNET AJAX Q2 2008\Bin
and
C:\Program Files\telerik\RadControls for ASPNET AJAX Q2 2008\Bin35

After I updated my project with the Telerik update tool from the upgrading step taking me from Q1 to Q2, the reference in the project was set to the Telerik.Web.UI in the Bin Directory (version 2008.2.826.20).

I noticed that there was also a Telerik.Web.UI dll in the Bin35 directory (version 2008.2.826.35)

Given that the Bin35 version was newer, I removed my reference from the Bin directory to the Bin35 directory.

That solved the problem.

Is this the correct solution ?

Please advise.

Thanks,

Robb Murdock

Hello RobbMurdock,

We are glad you were able to solve the problem yourself!

Yes, indeed. Please use the Bin35 .dll-s when developing under .Net3.5.

Sincerely yours,
Konstantin Petkov
the Telerik team

Hi

I am using "RadControls_for_ASP.NET_AJAX_2009_2_826_dev.msi" this Windows installer ...When ever i open to design it gives the Error Creatin ..Missing Telerick.Web.UI............We are using infragistic but we prefered to use Telerick but during the develop stage it gives all this Error..How can u support latter ....We are developing a big ERP ..do u think it can support for long term projects.....I have waste a night and a day in solving this issue i am not able to find..........How can you support me..........I need reply on this ...Please

Hello Chethan,

How to address design-time errors of this kind you can see from the online resources linked below:

http://blogs.telerik.com/atanaskorchev/posts/09-03-06/Meet_Telerik_Web_Design_dll.aspx

http://www.telerik.com/community/forums/aspnet-ajax/general-discussions/could-not-load-file-or-assembly-telerik-charting.aspx

Kind regards,
Sebastian
the Telerik team