Target class [guest] does not exist

Question

After downgrading my laravel version and i had to also downgraded laravel breeze version, but my login and register route gives an error which says Target class [guest] does not exist.

But in my protected $middlewareAliases I have a guest there but my auth.php isn't picking it.

Kernel.php

<?php

  namespace App\Http;

   use Illuminate\Foundation\Http\Kernel as HttpKernel;

    class Kernel extends HttpKernel
   {
     /**
      * The application's global HTTP middleware stack.
     *
      * These middleware are run during every request to your 
         application.
      *
       * @var array<int, class-string|string>
     */
     protected $middleware = [
    // \App\Http\Middleware\TrustHosts::class,
    \App\Http\Middleware\TrustProxies::class,
    \Illuminate\Http\Middleware\HandleCors::class,
    \App\Http\Middleware\PreventRequestsDuringMaintenance::class,
    \Illuminate\Foundation\Http\Middleware\ValidatePostSize::class,
    \App\Http\Middleware\TrimStrings::class,
    \Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,
];

/**
 * The application's route middleware groups.
 *
 * @var array<string, array<int, class-string|string>>
 */
protected $middlewareGroups = [
    'web' => [
        \App\Http\Middleware\EncryptCookies::class,
        \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
        \Illuminate\Session\Middleware\StartSession::class,
        \Illuminate\View\Middleware\ShareErrorsFromSession::class,
        \App\Http\Middleware\VerifyCsrfToken::class,
        \Illuminate\Routing\Middleware\SubstituteBindings::class,
    ],

    'api' => [
        // \Laravel\Sanctum\Http\Middleware\EnsureFrontendRequestsAreStateful::class,
        \Illuminate\Routing\Middleware\ThrottleRequests::class.':api',
        \Illuminate\Routing\Middleware\SubstituteBindings::class,
    ],
];

/**
 * The application's middleware aliases.
 *
 * Aliases may be used to conveniently assign middleware to routes and groups.
 *
 * @var array<string, class-string|string>
 */
protected $middlewareAliases = [
    'auth' => \App\Http\Middleware\Authenticate::class,
    'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
    'auth.session' => \Illuminate\Session\Middleware\AuthenticateSession::class,
    'cache.headers' => \Illuminate\Http\Middleware\SetCacheHeaders::class,
    'can' => \Illuminate\Auth\Middleware\Authorize::class,
    'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
    'password.confirm' => \Illuminate\Auth\Middleware\RequirePassword::class,
    'signed' => \App\Http\Middleware\ValidateSignature::class,
    'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
    'verified' => \Illuminate\Auth\Middleware\EnsureEmailIsVerified::class,
  ];
 }

In Auth.php

<?php

 use App\Http\Controllers\Auth\AuthenticatedSessionController;
 use App\Http\Controllers\Auth\ConfirmablePasswordController;
  use 
  App\Http\Controllers\Auth\EmailVerificationNotificationController;
  use App\Http\Controllers\Auth\EmailVerificationPromptController;
  use App\Http\Controllers\Auth\NewPasswordController;
  use App\Http\Controllers\Auth\PasswordController;
  use App\Http\Controllers\Auth\PasswordResetLinkController;
  use App\Http\Controllers\Auth\RegisteredUserController;
  use App\Http\Controllers\Auth\VerifyEmailController;
  use Illuminate\Support\Facades\Route;

 Route::middleware('guest')->group(function () {
  Route::get('register', [RegisteredUserController::class, 'create'])
            ->name('register');

Route::post('register', [RegisteredUserController::class, 'store']);

Route::get('login', [AuthenticatedSessionController::class, 'create'])
            ->name('login');

Route::post('login', [AuthenticatedSessionController::class, 'store']);

Route::get('forgot-password', [PasswordResetLinkController::class, 'create'])
            ->name('password.request');

Route::post('forgot-password', [PasswordResetLinkController::class, 'store'])
            ->name('password.email');

Route::get('reset-password/{token}', [NewPasswordController::class, 'create'])
            ->name('password.reset');

Route::post('reset-password', [NewPasswordController::class, 'store'])
            ->name('password.store');
});

 Route::middleware('auth')->group(function () {
  Route::get('verify-email', 
    EmailVerificationPromptController::class)
            ->name('verification.notice');

Route::get('verify-email/{id}/{hash}', VerifyEmailController::class)
            ->middleware(['signed', 'throttle:6,1'])
            ->name('verification.verify');

Route::post('email/verification-notification', [EmailVerificationNotificationController::class, 'store'])
            ->middleware('throttle:6,1')
            ->name('verification.send');

Route::get('confirm-password', [ConfirmablePasswordController::class, 'show'])
            ->name('password.confirm');

Route::post('confirm-password', [ConfirmablePasswordController::class, 'store']);

Route::put('password', [PasswordController::class, 'update'])->name('password.update');

Route::post('logout', [AuthenticatedSessionController::class, 'destroy'])
            ->name('logout');

});

Answer 1

For Laravel versions < 10, $middlewareAliases should be $routeMiddleware. So in Kernel.php file, try changing the name $middlewareAliases into $routeMiddleware.

protected $routeMiddleware = [
    'auth' => \App\Http\Middleware\Authenticate::class,
    'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
    'auth.session' => \Illuminate\Session\Middleware\AuthenticateSession::class,
    'cache.headers' => \Illuminate\Http\Middleware\SetCacheHeaders::class,
    'can' => \Illuminate\Auth\Middleware\Authorize::class,
    'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
    'password.confirm' => \Illuminate\Auth\Middleware\RequirePassword::class,
    'signed' => \App\Http\Middleware\ValidateSignature::class,
    'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
    'verified' => \Illuminate\Auth\Middleware\EnsureEmailIsVerified::class,
  ];
 }