I've tried going to 10.0.1 using Composer and then tried updating to 10.0.1 and get the same error message....
The website encountered an unexpected error. Please try again later.
Error: Class "Twig_Extension" not found in include() (line 12 of /home/customer/www/wiulibraries.org/public_html/video1/modules/entity_embed/src/Twig/EntityEmbedTwigExtension.php).
include() (Line: 571)
Composer\Autoload\includeFile('/home/customer/www/wiulibraries.org/public_html/video1/modules/entity_embed/src/Twig/EntityEmbedTwigExtension.php') (Line: 428)
Composer\Autoload\ClassLoader->loadClass('Drupal\entity_embed\Twig\EntityEmbedTwigExtension')
is_subclass_of('Drupal\entity_embed\Twig\EntityEmbedTwigExtension', 'Twig\Extension\ExtensionInterface') (Line: 181)
Drupal\Core\DependencyInjection\Compiler\TaggedHandlersPass->processServiceCollectorPass(Array, 'twig', Object) (Line: 116)
Drupal\Core\DependencyInjection\Compiler\TaggedHandlersPass->process(Object) (Line: 73)
Symfony\Component\DependencyInjection\Compiler\Compiler->compile(Object) (Line: 721)
Symfony\Component\DependencyInjection\ContainerBuilder->compile() (Line: 1307)
Drupal\Core\DrupalKernel->compileContainer() (Line: 911)
Drupal\Core\DrupalKernel->initializeContainer() (Line: 477)
Drupal\Core\DrupalKernel->boot() (Line: 679)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)
Any help would be appreciated..