Manually delete the bin and obj folders in your project directory.
Tip: If you don't have a Syncfusion account, you can create one for free and start a 30-day trial to generate a key.
To resolve the Syncfusion trial license key warning popup, you must register a valid license key in your application before any Syncfusion components are initialized.
import registerLicense from '@syncfusion/ej2-base'; // Register Syncfusion license registerLicense('YOUR_TRIAL_KEY_HERE'); Use code with caution. syncfusion trial license key fix
Console.WriteLine(SyncfusionLicenseProvider.LicenseStatus);
The license type (e.g., File Formats vs. Essential JS 2) is mismatched. Step 1: Generate the Correct License Key
: The license key must be registered at the very start of your application's lifecycle (e.g., in main.ts , Program.cs , or App.js ) before any Syncfusion components are rendered. Manually delete the bin and obj folders in
public static MauiApp CreateMauiApp() Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense("YOUR_ACTUAL_LICENSE_KEY_HERE"); var builder = MauiApp.CreateBuilder(); // Rest of your setup Use code with caution. Troubleshooting Common Errors Error: "The license key is invalid for this version"
var builder = WebApplication.CreateBuilder(args); // Register Syncfusion license Syncfusion.Licensing.SyncfusionLicenseProvider.RegisterLicense("YOUR_TRIAL_KEY_HERE"); var app = builder.Build(); Use code with caution. Windows Forms / WPF
This article is your definitive guide. We will cover why the error happens, the legitimate ways to fix it (including extending your trial), how to properly register the key in code, and how to troubleshoot the most obscure "license key not found" exceptions across .NET Framework, .NET Core, Blazor, and Xamarin. Step 1: Generate the Correct License Key :
This is the #1 reason the "fix" fails. If you updated your NuGet packages but kept an old license key, the warning will persist. Always refresh your key in the Syncfusion License & Downloads portal after an upgrade.
# Example script for validation $result = & $PSScriptRoot"\LicenseKeyValidatorConsole.exe" /platform:"Blazor" /version:"26.2.4" /licensekey:"Your License Key"
| Issue | Fix | |-------|-----| | “License key is invalid” | Re-copy key from account (no extra spaces). Ensure no line breaks. | | Still showing trial popup | Place registration any Syncfusion control is created/loaded. | | Expired immediately | Trial keys last 30 days . Generate a new trial key. | | NuGet package mismatch | Use latest NuGet packages matching your trial key version. | | Multiple projects | Register key once in startup project (for .NET). |
The license must be registered globally before the application renders any UI components.