Could not load file or assembly 'Telerik.Web.UI, version =2007.1.423.0 - blah blah blah

[timbersnow]

Hi,

Trying to add a RadAjaxManager to my page.  I'm getting the "Error Creating Control ... Could not load file or assembly 'Telerik ... " error.

I'm using VS 2005 Orcas and the v3.5 .NET framework ... I'm also using Vista x64 Enterprise ... and I also have the Microsoft AJAX Dev Toolkit installed.  I've also installed the SP1 for Prometheus 

BTW ... the RadAjaxmanager for RAD 2007 Q1 SP1 works fine ...

Cheers,

Gp.

[Shaun Peet]

I'm also getting the same errors, but I'm not using a system that advanced:

Vista Ultimate
VS 2005 Standard

The designer fails with all Prometheus controls.

[Alex Peachey]

I had the same problem. As far as I could tell, the issue happened if you upgraded to the SP1 release and just copied the new files over the old in both the install and your projects. For some reason, something in VS (any version) is holding on to the fact that you previously put an older version control on your page and now it doesn't like the fact that it is gone and you only have the newer version.

There is at least one fix, which is what I ended up doing. I did a full uninstall of the initial release and then installed the full SP1 version. That did the trick and everything was happy once again.

I can't really say why this was necessary or why it even worked, but that should get you going. Perhaps the Telerik folks have some comments once back from the holiday weekend.

[timbersnow]

Dude ... you rock.  I'll try this and let you know. 

Cheers,

Gp.

[hacker]

I am having the same problem and would like to avoid having to do a full un-install/re-install....

Has any other solution been found?

If not, then I will have to bite the bullet.


Shawn

[timbersnow]

Been there ... done that ... did NOT fix the issue.

I completely uninstalled VS, cleaned the registry, removed all of Telerik, reinstalled all ... SAME FREAKING THING.

Donno ... but i can save you the approximate 3 hour round trip to uninstall / reinstall.

Cheers,

Gp.

[Shaun Peet]

I'm fairly confident now that this is a GAC issue.

Follow this page:

http://www.telerik.com/help/radcontrols/prometheus/installAddToGlobalAssemblyCache.html

To add BOTH the telerik.web.design and the telerik.web.ui dlls into the GAC.  Viola, it started working.

[hacker]

Thanks Shaun!

That worked for me! 

Shawn

[Haderach]

Hello...

I have exactly the same problem but adding the 2 DLLs into GAC did not change anything....

Do you have any solution?

Thanks...

[Shaun Peet]

Have a look in your web.config and remove the telerik.web.ui assembly reference in the <assemblies> section, if it exists.

If that doesn't work, then have a look in the @register assebly of the page and make sure that it isn't referencing a specific version of the dll.

[Haderach]

Hello...

Thank you for your post but I check the 2 points and everything is good :

In my page I have :

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>

and in the Web.Config I have :

<assemblies>

<add assembly="Telerik.Web.Design, Version=1.0.0.0, Culture=neutral, PublicKeyToken=121FAE78165BA3D4"/>

<add assembly="System.Windows.Forms, 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.Configuration.Install, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>

<add assembly="ABCpdf, Version=5.0.0.8, Culture=neutral, PublicKeyToken=A7A0B3F5184F2169"/>

<add assembly="RssToolkit, Version=1.0.0.1, Culture=neutral, PublicKeyToken=02E47A85B237026A"/>

<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/></assemblies>

So what can I do ? Everything look good ... but not working....

[Shaun Peet]

Try removing the Telerik.Web.Design assembly from the web.config, and restart Visual Studio.

[Haderach]

Sorry but it is not working....
No change without Telerik.Web.Design assembly from the web.config

Any other idea ???

[Dave]

I had the error and it was the version that was incorrect in the register tag:-

I had <%@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI, Version=2008.1.512.20, Culture=neutral, PublicKeyToken=121fae78165ba3d4" %>

instead of

<%@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI, Version=2008.1.515.20, Culture=neutral, PublicKeyToken=121fae78165ba3d4" %>

I also had to change it in the safecontrol references - if I took the version out I got the same error as mentioned above.

[Ben]

Dude thanks a bunch. worked in seconds, It is so rare that you get a straight to the point fix to a problem anymore. This one rocks

[Phantom1024]

This one worked for me!
I just had to fix the dll references in my project.
it worked immediately in a new web application project.

Thanks,

Phantom1024

[Calvin Bowens]

For me, the fix was that for the references to Telerik.Web.Ui, I had copy local equal to false.  I changed it to true and then it worked.

[Danko]

That worked fine.

[Mark Bleshenski]

I had a similar problem.  I thought I would add my resolution.

In visual studio, the telerik controls came up with a box that said that it could not load assembly...blah blah

I tried to remove the Telerik.dll form the gac using gacutil.exe, but was told that other applications were dependent on it.  Finally i did the following steps:

Disabling the Assembly Cache Viewer

WARNING: The following steps involve modifying the Windows Registry. If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. The author as well as Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

If you want to disable the Assembly Cache Viewer and see the GAC in all its naked glory within Windows Explorer, you can set HKLM\Software\Microsoft\Fusion\DisableCacheViewer [DWORD] to 1. (these instructions were found on: http://www.codeproject.com/KB/dotnet/demystifygac.aspx)

This allowed me to see the actual files in the assembly folder.  I did a search on this folder for Telerik.

This listed several files and folders.  I deleted them.

When I opened Visual Studio, I could see all my controls just fine. 

I then went into the registry entry I added above and set the value to 0.

Looking at my assembly folder showed that it reverted to the default view. 

Everything works fine now.

[Jeff Berry]

Adding a reference to Telerik.Web.UI to the website and restarting Visual Studio fixed this for me.  Telerik.Web.UI exists in the Telerik install directory (under Program Files).  Throwing this in the GAC may be an option also.

[Matthew]

@Haderach: This is the answer right here. It's critical to have the proper assembly references in your web.config. Thanks. :)