The following error/stack trace is shown when simply navigating to url: /gii/crud
yii\base\ErrorException: Exception (Unknown Property) 'yii\base\UnknownPropertyException' with message 'Setting unknown property: yii\validators\FilterValidator::chars'
in /sites/test/v1/vendor/yiisoft/yii2/base/Component.php:209
Stack trace:
#0 /sites/test/v1/vendor/yiisoft/yii2/BaseYii.php(558): yii\base\Component->__set('chars', '\\ ')
#1 /sites/test/v1/vendor/yiisoft/yii2/base/BaseObject.php(107): yii\BaseYii::configure(Object(yii\validators\FilterValidator), Array)
#2 [internal function]: yii\base\BaseObject->__construct(Array)
#3 /sites/test/v1/vendor/yiisoft/yii2/di/Container.php(419): ReflectionClass->newInstanceArgs(Array)
#4 /sites/test/v1/vendor/yiisoft/yii2/di/Container.php(170): yii\di\Container->build('yii\\validators\\...', Array, Array)
#5 /sites/test/v1/vendor/yiisoft/yii2/BaseYii.php(365): yii\di\Container->get('yii\\validators\\...', Array, Array)
#6 /sites/test/v1/vendor/yiisoft/yii2/validators/Validator.php(231): yii\BaseYii::createObject(Array)
#7 /sites/test/v1/vendor/yiisoft/yii2/base/Model.php(468): yii\validators\Validator::createValidator(Array, Object(yii\gii\generators\crud\Generator), Array, Array)
#8 /sites/test/v1/vendor/yiisoft/yii2/base/Model.php(420): yii\base\Model->createValidators()
#9 /sites/test/v1/vendor/yiisoft/yii2/base/Model.php(189): yii\base\Model->getValidators()
#10 /sites/test/v1/vendor/yiisoft/yii2/base/Model.php(815): yii\base\Model->scenarios()
#11 /sites/test/v1/vendor/yiisoft/yii2/base/Model.php(434): yii\base\Model->activeAttributes()
#12 /sites/test/v1/vendor/yiisoft/yii2/base/Model.php(494): yii\base\Model->getActiveValidators('modelClass')
#13 /sites/test/v1/vendor/yiisoft/yii2/widgets/ActiveField.php(932): yii\base\Model->isAttributeRequired('modelClass')
#14 /sites/test/v1/vendor/yiisoft/yii2/widgets/ActiveField.php(405): yii\widgets\ActiveField->addAriaAttributes(Array)
#15 /sites/test/v1/vendor/yiisoft/yii2/widgets/ActiveField.php(207): yii\widgets\ActiveField->textInput()
#16 /sites/test/v1/vendor/yiisoft/yii2/widgets/ActiveField.php(176): yii\widgets\ActiveField->render()
#17 /sites/test/v1/vendor/yiisoft/yii2-gii/src/generators/crud/form.php(6): yii\widgets\ActiveField->__toString()
#18 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(347): require('/sites/test/v1/...')
#19 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(257): yii\base\View->renderPhpFile('/sites/test/v1/...', Array)
#20 /sites/test/v1/vendor/yiisoft/yii2-gii/src/views/default/view.php(43): yii\base\View->renderFile('/sites/test/v1/...', Array)
#21 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(347): require('/sites/test/v1/...')
#22 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(257): yii\base\View->renderPhpFile('/sites/test/v1/...', Array)
#23 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(156): yii\base\View->renderFile('/sites/test/v1/...', Array, Object(yii\gii\controllers\DefaultController))
#24 /sites/test/v1/vendor/yiisoft/yii2/base/Controller.php(407): yii\base\View->render('view', Array, Object(yii\gii\controllers\DefaultController))
#25 /sites/test/v1/vendor/yiisoft/yii2-gii/src/controllers/DefaultController.php(72): yii\base\Controller->render('view', Array)
#26 [internal function]: yii\gii\controllers\DefaultController->actionView('crud')
#27 /sites/test/v1/vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array(Array, Array)
#28 /sites/test/v1/vendor/yiisoft/yii2/base/Controller.php(178): yii\base\InlineAction->runWithParams(Array)
#29 /sites/test/v1/vendor/yiisoft/yii2/base/Module.php(552): yii\base\Controller->runAction('view', Array)
#30 /sites/test/v1/vendor/yiisoft/yii2/web/Application.php(103): yii\base\Module->runAction('gii/default/vie...', Array)
#31 /sites/test/v1/vendor/yiisoft/yii2/base/Application.php(384): yii\web\Application->handleRequest(Object(yii\web\Request))
#32 /sites/test/v1/frontend/web/index.php(31): yii\base\Application->run()
#33 {main} in /sites/test/v1/vendor/yiisoft/yii2/base/ErrorHandler.php:343
Stack trace:
#0 [internal function]: yii\base\ErrorHandler->handleError(256, 'Exception (Unkn...', '/sites/test/v1/...', 343, Array)
#1 /sites/test/v1/vendor/yiisoft/yii2/base/ErrorHandler.php(343): trigger_error('Exception (Unkn...', 256)
#2 /sites/test/v1/vendor/yiisoft/yii2/widgets/ActiveField.php(178): yii\base\ErrorHandler::convertExceptionToError(Object(yii\base\UnknownPropertyException))
#3 /sites/test/v1/vendor/yiisoft/yii2-gii/src/generators/crud/form.php(6): yii\widgets\ActiveField->__toString()
#4 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(347): require('/sites/test/v1/...')
#5 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(257): yii\base\View->renderPhpFile('/sites/test/v1/...', Array)
#6 /sites/test/v1/vendor/yiisoft/yii2-gii/src/views/default/view.php(43): yii\base\View->renderFile('/sites/test/v1/...', Array)
#7 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(347): require('/sites/test/v1/...')
#8 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(257): yii\base\View->renderPhpFile('/sites/test/v1/...', Array)
#9 /sites/test/v1/vendor/yiisoft/yii2/base/View.php(156): yii\base\View->renderFile('/sites/test/v1/...', Array, Object(yii\gii\controllers\DefaultController))
#10 /sites/test/v1/vendor/yiisoft/yii2/base/Controller.php(407): yii\base\View->render('view', Array, Object(yii\gii\controllers\DefaultController))
#11 /sites/test/v1/vendor/yiisoft/yii2-gii/src/controllers/DefaultController.php(72): yii\base\Controller->render('view', Array)
#12 [internal function]: yii\gii\controllers\DefaultController->actionView('crud')
#13 /sites/test/v1/vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array(Array, Array)
#14 /sites/test/v1/vendor/yiisoft/yii2/base/Controller.php(178): yii\base\InlineAction->runWithParams(Array)
#15 /sites/test/v1/vendor/yiisoft/yii2/base/Module.php(552): yii\base\Controller->runAction('view', Array)
#16 /sites/test/v1/vendor/yiisoft/yii2/web/Application.php(103): yii\base\Module->runAction('gii/default/vie...', Array)
#17 /sites/test/v1/vendor/yiisoft/yii2/base/Application.php(384): yii\web\Application->handleRequest(Object(yii\web\Request))
#18 /sites/test/v1/frontend/web/index.php(31): yii\base\Application->run()
#19 {main}
The error is solved by commenting out this line in \yii\gii\generators\crud\Generator::rules()
[['controllerClass', 'modelClass', 'searchModelClass', 'baseControllerClass'], 'trim', 'chars' => '\ '],
What is the cause and how to solve without modifying the vendor files?