110 words (approximately 1 min)

Overview

During development, when Blazor apps encounter an error, it displays a light yellow bar the bottom of the screen. Customize it in Pages/_Host.cshtml:

<div id="blazor-error-ui">
    <environment include="Staging,Production">
        An error has occurred. This application may no longer respond until reloaded.
    </environment>
    <environment include="Development">
        An unhandled exception has occurred. See browser dev tools for details.
    </environment>
    <a href="" class="reload">Reload</a>
    <a class="dismiss">🗙</a>
</div>

Detailed Circuit Errors

To get detailed circuit errors, set CircuitOptions.DetailedErrors to true, or set the DetailedErrors configuration key to true in appsettings.Development.json. Set SignalR server-side logging to Debug or Trace: appsettings.Development.json

{
    "DetailedErrors": true,
    "Logging": {
    "LogLevel": {
        "Default": "Information",
        "Microsoft": "Warning",
        "Microsoft.Hosting.Lifetime": "Information",
        "Microsoft.AspNetCore.SignalR": "Debug"
    }
    }
}