MissingControllerException (class Css)

Most requests generate the following stack trace, although without meaningfully affecting the application:

2021-04-24 14:40:15 Error: [Cake\Routing\Exception\MissingControllerException] C
ontroller class Css could not be found.
Exception Attributes: array (
'class' => 'Css',
'plugin' => false,
'prefix' => false,
'_ext' => false,
)
#0 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Contr
ollerFactory.php(39): Cake\Http\ControllerFactory->missingController(Object(Cake
\Http\ServerRequest))
#1 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/ActionDispatcher.php(91): Cake\Http\ControllerFactory->create(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response))
#2 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/BaseApplication.php(235): Cake\Http\ActionDispatcher->dispatch(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response))
#3 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Runner.php(65): Cake\Http\BaseApplication->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response), Object(Cake\Http\Runner))
#4 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Middleware/CsrfProtectionMiddleware.php(123): Cake\Http\Runner->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response))
#5 /media/sf_macsrc/comanage/git/match/app/src/Application.php(70): Cake\Http\Middleware\CsrfProtectionMiddleware->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response), Object(Cake\Http\Runner))
#6 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Runner.php(65): App\Application->App

(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response), Object(Cake\Http\Runner))
#7 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Routing/Middleware/RoutingMiddleware.php(162): Cake\Http\Runner->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response))
#8 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Runner.php(65): Cake\Routing\Middleware\RoutingMiddleware->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response), Object(Cake\Http\Runner))
#9 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Routing/Middleware/AssetMiddleware.php(97): Cake\Http\Runner->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response))
#10 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Runner.php(65): Cake\Routing\Middleware\AssetMiddleware->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response), Object(Cake\Http\Runner))
#11 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Error/Middleware/ErrorHandlerMiddleware.php(96): Cake\Http\Runner->__invoke(Object(Cake\Http\ServerRequest), Object(Cake\Http\Response))
#12 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Runn
er.php(65): Cake\Error\Middleware\ErrorHandlerMiddleware->__invoke(Object(Cake\H
ttp\ServerRequest), Object(Cake\Http\Response), Object(Cake\Http\Runner))
#13 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Runner.php(51): Cake\Http\Runner->__invoke(Object(Cake\Http\ServerRequest), Object(C
ake\Http\Response))
#14 /media/sf_macsrc/comanage/git/match/app/vendor/cakephp/cakephp/src/Http/Serv
er.php(98): Cake\Http\Runner->run(Object(Cake\Http\MiddlewareQueue), Object(Cake
\Http\ServerRequest), Object(Cake\Http\Response))
#15 /media/sf_macsrc/comanage/git/match/app/webroot/index.php(40): Cake\Http\Ser
ver->run()
#16 {main}
Request URL: /css/fonts/Font-Awesome-4.6.3/css/font-awesome.min.css
Referer URL: http://valkyrie.local/match/matchgrid-records?matchgrid_id=10