pl-k">endfor %}

After:

{% for field in fieldsWithPotentialDuplicates if not field.rendered %}
   {{ form_widget(field) }}
{% endfor %}

The regions option was removed from the TimezoneType.

FrameworkBundle

The project dir argument of the constructor of AssetsInstallCommand is required.

Removed support for bundle:controller:action syntax to reference controllers. Use serviceOrFqcn::method instead where serviceOrFqcn is either the service ID when using controllers as services or the FQCN of the controller.

Before:

bundle_controller:
    path: /
    defaults:
        _controller: FrameworkBundle:Redirect:redirect

After:

bundle_controller:
    path: /
    defaults:
        _controller: Symfony\Bundle\FrameworkBundle\Controller\RedirectController::redirectAction

Removed Symfony\Bundle\FrameworkBundle\Controller\ControllerNameParser.
Warming up a router in RouterCacheWarmer that does not implement the WarmableInterface is not supported anymore.
The RequestDataCollector class has been removed. Use the Symfony\Component\HttpKernel\DataCollector\RequestDataCollector class instead.
Removed Symfony\Bundle\FrameworkBundle\Controller\Controller. Use Symfony\Bundle\FrameworkBundle\Controller\AbstractController instead.
Added support for the SameSite attribute for session cookies. It is highly recommended to set this setting (framework.session.cookie_samesite) to lax for increased security against CSRF attacks.
The ContainerAwareCommand class has been removed, use Symfony\Component\Console\Command\Command with dependency injection instead.
The Templating\Helper\TranslatorHelper::transChoice() method has been removed, use the trans() one instead with a %count% parameter.
Removed support for legacy translations directories src/Resources/translations/ and src/Resources/<BundleName>/translations/, use translations/ instead.
Support for the legacy directory structure in translation:update and debug:translation commands has been removed.
Removed the "Psr\SimpleCache\CacheInterface" / "cache.app.simple" service, use "Symfony\Contracts\Cache\CacheInterface" / "cache.app" instead.

HttpFoundation

The $size argument of the UploadedFile constructor has been removed.
The getClientSize() method of the UploadedFile class has been removed.
The getSession() method of the Request class throws an exception when session is null.
The default value of the "$secure" and "$samesite" arguments of Cookie's constructor changed respectively from "false" to "null" and from "null" to "lax".
The MimeTypeGuesserInterface and ExtensionGuesserInterface interfaces have been removed, use Symfony\Component\Mime\MimeTypesInterface instead.
The MimeType and MimeTypeExtensionGuesser classes have been removed, use Symfony\Component\Mime\MimeTypes instead.
The FileBinaryMimeTypeGuesser class has been removed, use Symfony\Component\Mime\FileBinaryMimeTypeGuesser instead.
The FileinfoMimeTypeGuesser class has been removed, use Symfony\Component\Mime\FileinfoMimeTypeGuesser instead.

HttpKernel

Removed Client, use HttpKernelBrowser instead
The Kernel::getRootDir() and the kernel.root_dir parameter have been removed
The KernelInterface::getName() and the kernel.name parameter have been removed
Removed the first and second constructor argument of ConfigDataCollector
Removed ConfigDataCollector::getApplicationName()
Removed ConfigDataCollector::getApplicationVersion()
Removed FilterControllerArgumentsEvent, use ControllerArgumentsEvent instead
Removed FilterControllerEvent, use ControllerEvent instead
Removed FilterResponseEvent, use ResponseEvent instead
Removed GetResponseEvent, use RequestEvent instead
Removed GetResponseForControllerResultEvent, use ViewEvent instead
Removed GetResponseForExceptionEvent, use ExceptionEvent instead
Removed PostResponseEvent, use TerminateEvent instead
Removed TranslatorListener in favor of LocaleAwareListener

Intl

Removed ResourceBundle namespace
Removed Intl::getLanguageBundle(), use Languages or Scripts instead
Removed Intl::getCurrencyBundle(), use Currencies instead
Removed Intl::getLocaleBundle(), use Locales instead
Removed Intl::getRegionBundle(), use Countries instead

Messenger

The LoggingMiddleware class has been removed, pass a logger to SendMessageMiddleware instead.

Monolog

The methods DebugProcessor::getLogs(), DebugProcessor::countErrors(), Logger::getLogs() and Logger::countErrors() have a new $request argument.

Process

Removed the Process::setCommandline() and the PhpProcess::setPhpBinary() methods.

Commands must be defined as arrays when creating a Process instance.

Before:

$process = new Process('ls -l');

After:

$process = new Process(array('ls', '-l'));

// alternatively, when a shell wrapper is required
$process = Process::fromShellCommandline('ls -l');

Routing

The generator_base_class, generator_cache_class, matcher_base_class, and matcher_cache_class router options have been removed.
Route and CompiledRoute don't implement Serializable anymore; if you serialize them, please ensure your unserialization logic can recover from a failure related to an updated serialization format

Security

The Role and SwitchUserRole classes have been removed.
The getReachableRoles() method of the RoleHierarchy class has been removed. It has been replaced by the new getReachableRoleNames() method.
The getRoles() method has been removed from the TokenInterface. It has been replaced by the new getRoleNames() method.
The ContextListener::setLogoutOnUserChange() method has been removed.
The Symfony\Component\Security\Core\User\AdvancedUserInterface has been removed.
The ExpressionVoter::addExpressionLanguageProvider() method has been removed.
The FirewallMapInterface::getListeners() method must return an array of 3 elements, the 3rd one must be either a LogoutListener instance or null.
The AuthenticationTrustResolver constructor arguments have been removed.
A user object that is not an instance of UserInterface cannot be accessed from Security::getUser() anymore and returns null instead.
SimpleAuthenticatorInterface, SimpleFormAuthenticatorInterface, SimplePreAuthenticatorInterface, SimpleAuthenticationProvider, SimpleAuthenticationHandler, SimpleFormAuthenticationListener and SimplePreAuthenticationListener have been removed. Use Guard instead.
The ListenerInterface has been removed, turn your listeners into callables instead.
The Firewall::handleRequest() method has been removed, use Firewall::callListeners() instead.

\Serializable interface has been removed from AbstractToken and AuthenticationException, thus serialize() and unserialize() aren't available. Use __serialize() and __unserialize() instead.

Before:

public function serialize()
{
    return [$this->myLocalVar, parent::serialize()];
}

public function unserialize($serialized)
{
    [$this->myLocalVar, $parentSerialized] = unserialize($serialized);
    parent::unserialize($parentSerialized);
}

After:

public function __serialize(): array
{
    return [$this->myLocalVar, parent::__serialize()];
}

public function __unserialize(array $data): void
{
    [$this->myLocalVar, $parentData] = $data;
    parent::__unserialize($parentData);
}

The Argon2iPasswordEncoder class has been removed, use SodiumPasswordEncoder instead.
The BCryptPasswordEncoder class has been removed, use NativePasswordEncoder instead.
Classes implementing the TokenInterface must implement the two new methods __serialize and __unserialize

SecurityBundle

The logout_on_user_change firewall option has been removed.
The switch_user.stateless firewall option has been removed.
The SecurityUserValueResolver class has been removed.
Passing a FirewallConfig instance as 3rd argument to the FirewallContext constructor now throws a \TypeError, pass a LogoutListener instance instead.
The security.authentication.trust_resolver.anonymous_class parameter has been removed.
The security.authentication.trust_resolver.rememberme_class parameter has been removed.
The simple_form and simple_preauth authentication listeners have been removed, use Guard instead.
The SimpleFormFactory and SimplePreAuthenticationFactory classes have been removed, use Guard instead.
The names of the cookies configured in the logout.delete_cookies option are no longer normalized. If any of your cookie names has dashes they won't be changed to underscores. Before: my-cookie deleted the my_cookie cookie (with an underscore). After: my-cookie deletes the my-cookie cookie (with a dash).
Configuring encoders using argon2i or bcrypt as algorithm is not supported anymore, use auto instead.

Serializer

The AbstractNormalizer::handleCircularReference() method has two new $format and $context arguments.

Translation

The FileDumper::setBackup() method has been removed.
The TranslationWriter::disableBackup() method has been removed.
The TranslatorInterface has been removed in favor of Symfony\Contracts\Translation\TranslatorInterface
The MessageSelector, Interval and PluralizationRules classes have been removed, use IdentityTranslator instead
The Translator::getFallbackLocales() and TranslationDataCollector::getFallbackLocales() method are now internal
The Translator::transChoice() method has been removed in favor of using Translator::trans() with "%count%" as the parameter driving plurals

TwigBundle

The default value (false) of the twig.strict_variables configuration option has been changed to %kernel.debug%.
The transchoice tag and filter have been removed, use the trans ones instead with a %count% parameter.
Removed support for legacy templates directories src/Resources/views/ and src/Resources/<BundleName>/views/, use templates/ and templates/bundles/<BundleName>/ instead.

TwigBridge

removed the $requestStack and $requestContext arguments of the HttpFoundationExtension, pass a Symfony\Component\HttpFoundation\UrlHelper instance as the only argument instead

Validator

The checkMX and checkHost options of the Email constraint were removed
The Email::__construct() 'strict' property has been removed. Use 'mode'=>"strict" instead.
Calling EmailValidator::__construct() method with a boolean parameter has been removed, use EmailValidator("strict") instead.
Removed the checkDNS and dnsMessage options from the Url constraint.
The component is now decoupled from symfony/translation and uses Symfony\Contracts\Translation\TranslatorInterface instead
The ValidatorBuilderInterface has been removed and ValidatorBuilder is now final
Removed support for validating instances of \DateTimeInterface in DateTimeValidator, DateValidator and TimeValidator. Use Type instead or remove the constraint if the underlying model is type hinted to \DateTimeInterface already.
The symfony/intl component is now required for using the Bic, Country, Currency, Language and Locale constraints
The egulias/email-validator component is now required for using the Email constraint in strict mode
The symfony/expression-language component is now required for using the Expression constraint

Workflow

The DefinitionBuilder::reset() method has been removed, use the clear() one instead.
add method has been removed use addWorkflow method in Workflow\Registry instead.
SupportStrategyInterface has been removed, use WorkflowSupportStrategyInterface instead.
ClassInstanceSupportStrategy has been removed, use InstanceOfSupportStrategy instead.
MarkingStoreInterface::setMarking() has a third argument: array $context = [].
Removed support of initial_place. Use initial_places instead.

MultipleStateMarkingStore has been removed. Use MethodMarkingStore instead.

Before:

framework:
    workflows:
        type: workflow
        article:
            marking_store:
                type: multiple
                arguments: states

After:

framework:
    workflows:
        type: workflow
        article:
            marking_store:
                property: states

SingleStateMarkingStore has been removed. Use MethodMarkingStore instead.

Before:

framework:
    workflows:
        article:
            marking_store:
                arguments: state

After:

framework:
    workflows:
        article:
            marking_store:
                property: state

Support for using a workflow with a single state marking is dropped. Use a state machine instead.

Before:

framework:
    workflows:
        article:
            type: workflow
            marking_store:
                type: single_state

After:

framework:
    workflows:
        article:
            type: state_machine

Yaml

The parser is now stricter and will throw a ParseException when a mapping is found inside a multi-line string.