Syncfusion® Essential Studio® Release Notes
Starting with version 16.2 (2018 Vol 2), you need to include a valid license key (either paid or trial key) within your applications.
Please refer to this help topic for more information
We have removed the Syncfusion® Licensing NuGet package v20.4.0.40 from the nuget.org due to an issue with it. To resolve any compilation issues or warnings while using this, upgrade your Syncfusion® NuGet packages version to v20.4.0.41 or later.