.NET MAUI › Troubleshooting & Common Errors
Why do I get a 'handler not found' or blank custom control?
IntermediateAnswer
The custom handler isn't registered, or CreatePlatformView returns nothing for a platform. Register handlers in MauiProgram via ConfigureMauiHandlers(h => h.AddHandler(typeof(MyControl), typeof(MyHandler))), and ensure every target platform has an implementation.
builder.ConfigureMauiHandlers(h =>
h.AddHandler(typeof(MyControl), typeof(MyControlHandler)));Real-world example A blank custom control appears until the team registers its handler in MauiProgram for all platforms.