It throws an error when there is an unexpected value in the URL.

[benfiratkaya]

It throws an error when there is an unexpected value in the URL. And try catch not working.

    try {
      SimpleRouter::start();
    } catch (Expception $ex) {
      echo $ex->getMessage(); // NOT WORKING!
    }

URL: /dashboard/accounts/"/
Error:

Fatal error: Uncaught TypeError: Typed property Pecee\SimpleRouter\Route\Route::$parameters must be array, null used in /Users/firatkaya/PhpstormProjects/leaderos-v5-global/apps/dashboard/vendor/pecee/simple-router/src/Pecee/SimpleRouter/Route/RouteResource.php:109 Stack trace: #0 /Users/firatkaya/PhpstormProjects/leaderos-v5-global/apps/dashboard/vendor/pecee/simple-router/src/Pecee/SimpleRouter/Router.php(389): Pecee\SimpleRouter\Route\RouteResource->matchRoute('/dashboard/acco...', Object(Pecee\Http\Request)) #1 /Users/firatkaya/PhpstormProjects/leaderos-v5-global/apps/dashboard/vendor/pecee/simple-router/src/Pecee/SimpleRouter/Router.php(353): Pecee\SimpleRouter\Router->routeRequest() #2 /Users/firatkaya/PhpstormProjects/leaderos-v5-global/apps/dashboard/vendor/pecee/simple-router/src/Pecee/SimpleRouter/SimpleRouter.php(69): Pecee\SimpleRouter\Router->start() #3 /Users/firatkaya/PhpstormProjects/leaderos-v5-global/apps/dashboard/public/index.php(897): Pecee\SimpleRouter\SimpleRouter::start() #4 /Users/firatkaya/Phpsto in /Users/firatkaya/PhpstormProjects/leaderos-v5-global/apps/dashboard/vendor/pecee/simple-router/src/Pecee/SimpleRouter/Route/RouteResource.php on line 109

[ms-afk]

The try/catch block is not working because you have mistyped Exception as Expception.
As for the error itself, I don't get that in my app, so it must have something to do with how you have set up your routes.