Hi Aaron,
Our license
keys are version and platform-specific and it’s just a string that needs
to be registered before initiating any Syncfusion controls in your application.
So,
please register the license key before initializing our controls. Also, please ensure that all the
referenced Syncfusion assemblies\NuGet packages are on the same version as
license key’s version
To know about generating license key,
https://help.syncfusion.com/aspnet-core/licensing/generating-license-keys
To know about registering license key,
https://help.syncfusion.com/aspnet-core/licensing/registering-license-keys

We had a problem with the region date and time format
while validating the license in v20.1.0.47. This problem has already been
fixed, and it has been included in v20.1.0.48.
Please update the Syncfusion.licensing and all the referred
Syncfusion NuGet packages to the latest v20.1.0.48 or later and check
whether the issue resolves.
If still the problem is not resolved, please share the following details.
- List of Syncfusion assemblies\nuget
packages referred and its version
- License key registered in the application.
- Screenshot of issue you’re facing and
license key registered place
Regards,
Jeyaseelan M