Deprecated function: mb_convert_encoding()

Problem/Motivation

I am seeing this frequently:

Deprecated function: mb_convert_encoding(): Passing null to parameter #1 ($string) of type array|string is deprecated in Drupal\Component\Transliteration\PhpTransliteration->transliterate() (line 142 of /core/lib/Drupal/Component/Transliteration/PhpTransliteration.php)
#0 /core/includes/bootstrap.inc(166): _drupal_error_handler_real()
#1 [internal function]: _drupal_error_handler()
#2 /core/lib/Drupal/Component/Transliteration/PhpTransliteration.php(142): mb_convert_encoding()
#3 /modules/contrib/paragraphs_jquery_ui_accordion/src/Plugin/Field/FieldFormatter/ParagraphsJQueryUIAccordionFormatter.php(307): Drupal\Component\Transliteration\PhpTransliteration->transliterate()
#4 /core/lib/Drupal/Core/Field/FormatterBase.php(91): Drupal\paragraphs_jquery_ui_accordion\Plugin\Field\FieldFormatter\ParagraphsJQueryUIAccordionFormatter->viewElements()
#5 /core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/EntityReferenceFormatterBase.php(76): Drupal\Core\Field\FormatterBase->view()
#6 /core/lib/Drupal/Core/Entity/Entity/EntityViewDisplay.php(268): Drupal\Core\Field\Plugin\Field\FieldFormatter\EntityReferenceFormatterBase->view()
#7 /core/lib/Drupal/Core/Entity/EntityViewBuilder.php(340): Drupal\Core\Entity\Entity\EntityViewDisplay->buildMultiple()
#8 /core/lib/Drupal/Core/Entity/EntityViewBuilder.php(282): Drupal\Core\Entity\EntityViewBuilder->buildComponents()
#9 /core/lib/Drupal/Core/Entity/EntityViewBuilder.php(239): Drupal\Core\Entity\EntityViewBuilder->buildMultiple()
#10 [internal function]: Drupal\Core\Entity\EntityViewBuilder->build()
#11 /modules/contrib/commerce/modules/product/src/ProductVariationFieldRenderer.php(37): call_user_func()
#12 /modules/contrib/commerce/modules/product/src/ProductViewBuilder.php(96): Drupal\commerce_product\ProductVariationFieldRenderer->renderFields()
#13 /core/lib/Drupal/Core/Entity/EntityViewBuilder.php(292): Drupal\commerce_product\ProductViewBuilder->alterBuild()
#14 /core/lib/Drupal/Core/Entity/EntityViewBuilder.php(239): Drupal\Core\Entity\EntityViewBuilder->buildMultiple()
#15 [internal function]: Drupal\Core\Entity\EntityViewBuilder->build()
#16 /core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php(113): call_user_func_array()
#17 /core/lib/Drupal/Core/Render/Renderer.php(870): Drupal\Core\Render\Renderer->doTrustedCallback()
#18 /core/lib/Drupal/Core/Render/Renderer.php(432): Drupal\Core\Render\Renderer->doCallback()
#19 /core/lib/Drupal/Core/Render/Renderer.php(248): Drupal\Core\Render\Renderer->doRender()
#20 /core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(238): Drupal\Core\Render\Renderer->render()
#21 /core/lib/Drupal/Core/Render/Renderer.php(638): Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}()
#22 /core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(231): Drupal\Core\Render\Renderer->executeInRenderContext()
#23 /core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(128): Drupal\Core\Render\MainContent\HtmlRenderer->prepare()
#24 /core/lib/Drupal/Core/EventSubscriber/MainContentViewSubscriber.php(90): Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse()
#25 [internal function]: Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray()
#26 /core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(111): call_user_func()
#27 /vendor/symfony/http-kernel/HttpKernel.php(186): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch()
#28 /vendor/symfony/http-kernel/HttpKernel.php(76): Symfony\Component\HttpKernel\HttpKernel->handleRaw()
#29 /core/lib/Drupal/Core/StackMiddleware/Session.php(53): Symfony\Component\HttpKernel\HttpKernel->handle()
#30 /core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle()
#31 /core/lib/Drupal/Core/StackMiddleware/ContentLength.php(28): Drupal\Core\StackMiddleware\KernelPreHandle->handle()
#32 /core/modules/big_pipe/src/StackMiddleware/ContentLength.php(32): Drupal\Core\StackMiddleware\ContentLength->handle()
#33 /core/modules/page_cache/src/StackMiddleware/PageCache.php(191): Drupal\big_pipe\StackMiddleware\ContentLength->handle()
#34 /core/modules/page_cache/src/StackMiddleware/PageCache.php(128): Drupal\page_cache\StackMiddleware\PageCache->fetch()
#35 /core/modules/page_cache/src/StackMiddleware/PageCache.php(82): Drupal\page_cache\StackMiddleware\PageCache->lookup()
#36 /core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle()
#37 /core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle()
#38 /core/lib/Drupal/Core/StackMiddleware/AjaxPageState.php(36): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle()
#39 /core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(51): Drupal\Core\StackMiddleware\AjaxPageState->handle()
#40 /core/lib/Drupal/Core/DrupalKernel.php(741): Drupal\Core\StackMiddleware\StackedHttpKernel->handle()
#41 /index.php(19): Drupal\Core\DrupalKernel->handle()
#42 {main}
.