Developer licenses come with modified DLLs, which work without license keys. If you have a Developer license for one or more of the Telerik products, 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 reports are displaying a copyright message, this means that you are using a trial version of the product. Log in to your Telerik account and download the developer build. To update your project, please take a look at the Upgrading Telerik Reporting Trial to Telerik Reporting Developer 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 a copyright message displayed on each report page.