Class PageNotFoundException not found

Have a look at App/config/Filters.php

heres mine

Code:

public array $aliases = [
        'csrf'          => CSRF::class,
        'toolbar'       => DebugToolbar::class,
        'honeypot'      => Honeypot::class,
        'invalidchars'  => InvalidChars::class,
        'secureheaders' => SecureHeaders::class,
        'cors'          => Cors::class,
        'forcehttps'    => ForceHTTPS::class,
        'pagecache'     => PageCache::class,
        'performance'   => PerformanceMetrics::class,
         'myfilter'=> \App\Filters\MyFilter::class
    ];

i am defining MyFilter.php class as "myfilter" ; shield uses filters so have a quick look.

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