Are you are a licensed developer but you still sometimes get the trial message when you run a page with RadControls for ASP.NET AJAX?


   Telerik.Web.UI 2012.X.XXX.XX trial version. Copyright Telerik © 2002-2012. To remove this message, please purchase a developer version.


This error means that you are still using the trial version of Telerik.Web.UI.dll! There is a couple of different ways to check whether the Telerik.Web.UI.dll assembly is a trial or a purchased one:

  • Bin folder: Open the bin folder of your project using Windows Explorer and right click on the Telerik.Web.UI.dll file -> choose Properties -> go to the Details tab. If the assembly is trial one the file description field will show: Telerik.Web.UI.dll Trial Version. In this case you need to replace it with the purchased version from your RadControls for ASP.NET AJAX installation folder or from a hotfix ZIP you downloaded from our site.
  • GAC: The Global Assembly Cache for .NET 4.0 DLLs is located in the following Windows folder %windir%\Microsoft.NET\assembly\. You can open it in Windows explorer, locate the Telerik.Web.UI.dll and check it using the steps provided above for the Bin folder.
    GAC .NET 4.0
    The Global Assembly Cache for .NET 2.0 and 3.5 apps is placed in the %windir%\assembly\ directory. Load it in Window Explorer -> locate Telerik.Web.UI in the Assembly Name column and choose Properties by right clicking over the assembly name -> go to the Version tab -> check the value of the Description field. If it reads Telerik.Web.UI Trial Version then you need to replace it - remove the old version from the GAC first and then install the purchased one. Note that any currently active web applications might need to be restarted to see the new assembly in the GAC.
    GAC .NET 2.0 and 3.5
  • Visual Studio: Expand the bin folder in the Solution Explorer pane and double click over the Telerik.Web.UI.dll -> this will open a treeview with the dll name and its version folder in the central pane of Visual Studio -> expand the Version folder and double click on the 1 [neutral] item -> check the File Description field. If it reads Telerik.Web.UI Trial Version you will need to remove the Telerik.Web.UI reference from your project and update it with the purchased version.
    Visual Studio assembly properties
  • Telerik VSExtensions Options: If the highlighted option on the screenshot below is enabled, the Telerik Extensions for Visual Studio will notify you that the Telerik.Web.UI.DLL used in the project is trial and will suggest to replace it if an equal purchased version is installed on the machine or available in the %appdata%\telerik\updates location.
    Telerik Extensions for Visual Studio


If you download your files from your account, make sure that they are DEV (the purchased) builds, to ensure that you not see a trial message, e.g.


If you have installed a trial build (.msi), it is recommended to uninstall it completely, download the Dev executable from your account and install it. More information on the subject is available in the following help article: Upgrading RadControls Trial to RadControls Developer license or newer version.

About the Author

Stoyan Stratev

is a technical lead in the Windows 8 HTML team at Telerik. He joined the company in 2005 as a web developer, specializing in the integration of the Telerik components in third-party solutions, such as DotNetNuke and SharePoint. He led one of the ASP.NET AJAX teams before moving on to the Windows 8 division.

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