Could not load file or assembly 'Telerik.Web.UI' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

[Alan]

So basically when I run my ASP.NET project I get this error, the thing is I used to get this error with Newtonsoft.Json, so what I did I went to my web.config and checked the <bindingRedirect>

<dependentAssembly>
<assemblyIdentityname="Telerik.Web.UI" publicKeyToken="" culture="neutral" />
<bindingRedirectoldVersion="0.0.0.0-2020.2.617.45" newVersion="2020.2.617.45" />
</dependentAssembly>

So after I went to references and checked if the version matched with the web config and it did

 

 

                     

[Vessy]

Hello,

Тhe thrown error usually indicates that the project is keeping a reference to the previously used version of the controls.

Can you open the licenses.licx file of your project, delete its content, save it and try to built the project again?

If the error persists, please, open the *.proj file of your application in a text redactor and search for the problematic Telerik version there? Sometimes Visual Studio fails in upgrading this file which results in such errors.

Another thing I can suggest you is to clear the temporary ASP.NET files on your machine, they can be found in a similar location:
%windir%\Microsoft.NET\Framework\v2.0.50727
%windir%\Microsoft.NET\Framework\v4.0.30319

 

Regards,
Vessy
Progress Telerik