The following topic will explain you the main differences between the licenses available for the Telerik UI for WPF and the limitations of the Trial License.
Currently there are two types of licenses used for UI for WPF:
Developer licenses come with modified DLLs, which work without license keys. If you have a Developer license for one or more of the Telerik components, you only need to ensure that you are using the developer build when downloading the control(s). These builds have the Dev abbreviation in their file names.
If your application is displaying a license key error, this means that you are using a trial version of the product. Log in to your Client.net account and download the developer build. To update your project, please take a look at the Upgrading the Trial License to a Production License section for step-by-step instructions.
The free trial licenses of all Telerik products are fully functional and will work for an unlimited time but with trial error messages (see below) displayed randomly on the page.
The trial licenses will occasionally display the following message on your application:
Telerik UI for WPF trial version. Copyright Telerik © 2002-2014. To remove this message, please, purchase a developer version.