Could not load file or assembly 'Telerik.Web.UI' or one of its dependencies. The system cannot find the file specified.

[Mohamed]

i'm so new on telerik
i downloaded telerik tools trial few days ago and i create new web site and try the radgrid so well on the local server
when i put the files on the real server it gives the follwing errors messages
Parser ErrorDescription: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately. 

Parser Error Message: Could not load file or assembly 'Telerik.Web.UI' or one of its dependencies. The system cannot find the file specified.

Source Error: 

Line 1: <%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Default6.aspx.cs" Inherits="Default6" %>
Line 2:
Line 3: <%@ Register assembly="Telerik.Web.UI" namespace="Telerik.Web.UI" tagprefix="telerik" %>
Line 4:
Line 5: <asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
Source File: /investmentweb5/tajheer/Default6.aspx    Line: 3 

Assembly Load Trace: The following information can be helpful to determine why the assembly 'Telerik.Web.UI' 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].

[Miika]

Hi,

I got the same error on server after publishing a working web site with a new version of Telerik.Web.UI.

Solved by checking the "delete all existing files prior to publish" from file publish options. (dll was probably not overwritten on server correctly).

[Rumen]

Thank you for sharing your solution with the community, Miika! This is much appreciated!

[Shinu]

Hi Mohamed,

I have found the following forum link which discusses a similar error. Go through it and see if it is helps.

Could not load file or assembly 'Telerik.Web.UI' or one of its dependencies. The system cannot find the file specified
Could not load file or assembly 'Telerik.Web.UI'

Thanks,
Shinu.

[Stephen]

I know this is an old post, but I am getting the same error even after trying to run the gacutil (which doesn't seem to work). Is there an updated method since it is 4 years later?

[Pavlina]

Hello,

Such an error usually means that Telerik.Web.UI assembly is not properly referenced. For example the assembly is placed in the BIN folder but the project is referencing it from the GAC or vice versa. It may also be possible that a binding redirect is used which also refers to the wrong .dll version. Therefore, I suggest you revise the .dll references of your project. 

If this not helps would be better to isolate the issue in a fully runnable sample and then provide it back to us, so we can investigate it further.

 

Regards,
Pavlina
Telerik

[Stephen]

I will check into that and let you know, Tavlina. Thank you so much for the quick response.

 

Steve

The Rushmore Group

[Pavlina]

Hello,

I hope you will manage to resolve the problem. In case you need additional assistance let me know.

Regards,
Pavlina
Telerik

[Tanja]

Mybe some other People can help this:

Be sure u define Version, Culture and PublicKeyToken

<%@ Register Assembly="Telerik.Web.UI, Version=2016.2.504.45, Culture=neutral, PublicKeyToken=xxxxxxxxx" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>

[Rajesh]

Hi,

Try adding that telerik.web.ui dll in the bin folder of your solution manually.

It worked for me. I am adding in the refernece but its not taking. So, I have added manually in the bin folder.

Thanks,

[Rumen]

Hi Rajesh,

Can you please explain in more detail what problem do you experience and provide a video or screenshots of:

• the error
• the steps that you follow?

What type is your web project: ASP.NET Web Site or ASP.NET Web Application?

Best regards,
Rumen
Progress Telerik

[Victor]

This worked for me after hours of trying all other fixes.

1. Remove all Telerik.Web.Design assemblies from the GAC using the Gacutil.exe tool. Use gacutil /u Telerik.Web.Design command for this purpose. Have in mind that it is required to execute the command as an administrator (run the Developer Command Prompt as an administrator and execute the command).

2. Clean your Visual Studio solution and make sure the bin folders are empty.

3. Update your projects using the Upgrade Wizard.

 

found here:

error during upgrade: Please, use the GAC reference instead in UI for ASP.NET MVC | Telerik Forums

[Vessy]

Thank you for the shared solution, Victor.

You can also find useful information on this matter here: System.IO.FileLoadException: Could not load file or assembly 'Telerik.Web.UI