Unique Field Ajax php 8.1 - Deprecated function mb_strtolower

Problem/Motivation

D 9.4.6 php 8.1

location: /admin/structure/taxonomy/manage/company/overview/fields/taxonomy_term.company.field_company_kurzel

Deprecated function: mb_strtolower(): Passing null to parameter #1 ($string) of type string is deprecated in Drupal\Core\Config\Entity\Query\Condition->compile() (line 39 of /web/core/lib/Drupal/Core/Config/Entity/Query/Condition.php)

#0 /web/core/includes/bootstrap.inc(347): _drupal_error_handler_real()
#1 [internal function]: _drupal_error_handler()
#2 /web/core/lib/Drupal/Core/Config/Entity/Query/Condition.php(39): mb_strtolower()
#3 /web/core/lib/Drupal/Core/Config/Entity/Query/Query.php(85): Drupal\Core\Config\Entity\Query\Condition->compile()
#4 /web/modules/contrib/unique_field_ajax/unique_field_ajax.module(652): Drupal\Core\Config\Entity\Query\Query->execute()
#5 /web/modules/contrib/unique_field_ajax/unique_field_ajax.module(572): unique_field_ajax_is_unique()
#6 [internal function]: unique_field_ajax_validate_unique()
#7 /web/core/lib/Drupal/Core/Form/FormValidator.php(282): call_user_func_array()
#8 /web/core/lib/Drupal/Core/Form/FormValidator.php(238): Drupal\Core\Form\FormValidator->doValidateForm()
#9 /web/core/lib/Drupal/Core/Form/FormValidator.php(238): Drupal\Core\Form\FormValidator->doValidateForm()
#10 /web/core/lib/Drupal/Core/Form/FormValidator.php(238): Drupal\Core\Form\FormValidator->doValidateForm()
#11 /web/core/lib/Drupal/Core/Form/FormValidator.php(238): Drupal\Core\Form\FormValidator->doValidateForm()
#12 /web/core/lib/Drupal/Core/Form/FormValidator.php(118): Drupal\Core\Form\FormValidator->doValidateForm()
#13 /web/core/lib/Drupal/Core/Form/FormBuilder.php(588): Drupal\Core\Form\FormValidator->validateForm()
#14 /web/core/lib/Drupal/Core/Form/FormBuilder.php(320): Drupal\Core\Form\FormBuilder->processForm()
#15 /web/core/lib/Drupal/Core/Controller/FormController.php(73): Drupal\Core\Form\FormBuilder->buildForm()
#16 /web/core/modules/layout_builder/src/Controller/LayoutBuilderHtmlEntityFormController.php(39): Drupal\Core\Controller\FormController->getContentResult()
#17 [internal function]: Drupal\layout_builder\Controller\LayoutBuilderHtmlEntityFormController->getContentResult()
#18 /web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array()
#19 /web/core/lib/Drupal/Core/Render/Renderer.php(564): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#20 /web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(124): Drupal\Core\Render\Renderer->executeInRenderContext()
#21 /web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext()
#22 /web/vendor/symfony/http-kernel/HttpKernel.php(159): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#23 /web/vendor/symfony/http-kernel/HttpKernel.php(81): Symfony\Component\HttpKernel\HttpKernel->handleRaw()
#24 /web/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle()
#25 /web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle()
#26 /web/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle()
#27 /web/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass()
#28 /web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle()
#29 /web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle()
#30 /web/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle()
#31 /web/core/lib/Drupal/Core/DrupalKernel.php(709): Stack\StackedHttpKernel->handle()
#32 /web/index.php(19): Drupal\Core\DrupalKernel->handle()
#33 {main}

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes