I started to have this ussue after uprading core from 10.2 to 10.3.
Using Webform 6.2.3
Upgrading webform did not solved the problem
InvalidArgumentException: "select" is an invalid render array key. Value should be an array but got a string. in Drupal\Core\Render\Element::children() (linea 97 di /var/www/crm/testing/crmdev.wikimedia.it/web/core/lib/Drupal/Core/Render/Element.php).
#0 /var/www/crm/testing/crmdev.wikimedia.it/web/core/lib/Drupal/Core/Render/Renderer.php(462): Drupal\Core\Render\Element::children()
#1 /var/www/crm/testing/crmdev.wikimedia.it/web/core/lib/Drupal/Core/Render/Renderer.php(248): Drupal\Core\Render\Renderer->doRender()
#2 /var/www/crm/testing/crmdev.wikimedia.it/web/core/lib/Drupal/Core/Render/Renderer.php(165): Drupal\Core\Render\Renderer->render()
#3 /var/www/crm/testing/crmdev.wikimedia.it/web/core/lib/Drupal/Core/Render/Renderer.php(638): Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}()
#4 /var/www/crm/testing/crmdev.wikimedia.it/web/core/lib/Drupal/Core/Render/Renderer.php(164): Drupal\Core\Render\Renderer->executeInRenderContext()
#5 /var/www/crm/testing/crmdev.wikimedia.it/web/core/lib/Drupal/Core/Render/Renderer.php(174): Drupal\Core\Render\Renderer->renderInIsolation()
#6 /var/www/crm/testing/crmdev.wikimedia.it/web/modules/contrib/webform/webform.tokens.inc(1077): Drupal\Core\Render\Renderer->renderPlain()
#7 /var/www/crm/testing/crmdev.wikimedia.it/web/modules/contrib/webform/webform.tokens.inc(743): _webform_token_get_submission_value()
#8 [internal function]: webform_tokens()
nessollo → created an issue.
Here a problem reported in Durpal Core 10.2.6:
https://www.drupal.org/forum/support/upgrading-drupal/2024-05-02/upgradi... →
Same problem here.
Updating to Drupal Core 10.2.6 the core CSS aggregation feature broke the websites.
The compressed CSS are unavailable and respond with a 400 error.
The problem is NOT theme related because it happen both in front-end theme then backend one.
Rolling back to Drupal Core 10.2.5 solved the issue.
nessollo → created an issue.