We have introduced a new licensing system starting with version 16.2.0.x release of Essential Studio. These modifications apply to all evaluators and only to paid customers who use NuGet packages from nuget.org. Starting with v16.2.0.x, if you use the evaluation installer or the NuGet feed to reference Syncfusion assemblies, you must also include the corresponding platform and version license key in your projects.
Please note that this license key is different from the installer unlock key that you might have used in the past and needs to be separately generated from Syncfusion website. Refer this KB article to know more about difference between the Syncfusion Unlock Key and the Syncfusion License Key.
Following licensing error will be shown if the license key is not registered in your projects, while using assemblies from evaluation installer or from the nuget.org
This application was built using a trial version of Syncfusion Essential Studio. Please include a valid license to permanently remove this license validation message. You can also obtain a free 30 day evaluation license to temporarily remove this message during the evaluation period. Please refer to this help topic for more information.