Why does my custom debug launch profile in Blazor omit the MainLayout?

When you change the environment name to a custom string (in your case, "DevelopmentPK") the built‐in checks that use Environment.IsDevelopment() no longer return true. By default, IsDevelopment() only returns true when ASPNETCORE_ENVIRONMENT is set exactly to "Development" (ignoring case).

In your Blazor Server App template the framework (or your startup code) is likely using a statement such as:

CSHARPCopied
if (app.Environment.IsDevelopment())
{
    // Register services, middleware, or settings (including UI/layout configuration)
}
else
{
    // Production (or non‑Development) configuration
}

Because "DevelopmentPK" isn’t equal to "Development", the app skips the “development” configuration. That is why your MainLayout (and possibly other related UI settings) isn’t being applied when you launch with the devPK launch profile.

How to Prevent It

You have a couple of options:

1. Standardize on "Development":
   Use the built‑in “Development” environment name (and rely on appsettings.Development.json) for your debug scenario. If you need different connection strings or paths, you could consider using configuration sections or additional configuration files loaded explicitly rather than a custom environment name.

2. Customize Environment Checks:
   If you must use a custom environment (like "DevelopmentPK"), then update your startup logic (often in Program.cs) so that it treats your custom environment as a development environment. For example, you can modify the condition to check if the environment name starts with "Development". For instance:

   CSHARPCopied
   if (app.Environment.EnvironmentName.StartsWith("Development", StringComparison.OrdinalIgnoreCase))
   {
       // Development configuration, which now also applies to "DevelopmentPK"
       // e.g., register the full UI including MainLayout etc.
   }
   else
   {
       // Non-development configuration
   }

This change ensures that your custom environment name is treated in the same way as the default "Development" environment and your full UI (including MainLayout.razor) will be used.

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By ensuring your environment check aligns with the custom value, you can use multiple debug launch profiles (and corresponding appsettings files) without running into issues with your UI being loaded incorrectly.