Error with commerce_simple_stock module

Hello, guys!
Thanks for great module!
Previously, the module worked perfect.
However, when I install the commerce_simple_stock → module into the system, the following errors appeared in site's logs:

Error: Call to a member function getQuantity() on null в Drupal\commerce_simple_stock\EventSubscriber\OrderEventSubscriber->preSaveOrderItem() (row 120 of /home/s/savage5706/kypiopt/public_html/web/modules/contrib/commerce_simple_stock/src/EventSubscriber/OrderEventSubscriber.php)
#0 [internal function]: Drupal\commerce_simple_stock\EventSubscriber\OrderEventSubscriber->preSaveOrderItem(Object(Drupal\commerce_order\Event\OrderItemEvent), 'commerce_order....', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#1 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(111): call_user_func(Array, Object(Drupal\commerce_order\Event\OrderItemEvent), 'commerce_order....', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#2 /home/s/savage5706/kypiopt/public_html/web/modules/contrib/commerce/src/CommerceContentEntityStorage.php(104): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('commerce_order....', Object(Drupal\commerce_order\Event\OrderItemEvent))
#3 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/Entity/EntityStorageBase.php(500): Drupal\commerce\CommerceContentEntityStorage->invokeHook('presave', Object(Drupal\commerce_order\Entity\OrderItem))
#4 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php(700): Drupal\Core\Entity\EntityStorageBase->doPreSave(Object(Drupal\commerce_order\Entity\OrderItem))
#5 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/Entity/EntityStorageBase.php(454): Drupal\Core\Entity\ContentEntityStorageBase->doPreSave(Object(Drupal\commerce_order\Entity\OrderItem))
#6 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php(837): Drupal\Core\Entity\EntityStorageBase->save(Object(Drupal\commerce_order\Entity\OrderItem))
#7 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/Entity/EntityBase.php(395): Drupal\Core\Entity\Sql\SqlContentEntityStorage->save(Object(Drupal\commerce_order\Entity\OrderItem))
#8 /home/s/savage5706/kypiopt/public_html/web/modules/contrib/commerce_repeat_order/src/Controller/CommerceRepeatOrder.php(93): Drupal\Core\Entity\EntityBase->save()
#9 [internal function]: Drupal\commerce_repeat_order\Controller\CommerceRepeatOrder->repeatOrder(Object(Drupal\commerce_order\Entity\Order))
#10 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array(Array, Array)
#11 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/Render/Renderer.php(573): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#12 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(124): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#13 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array)
#14 /home/s/savage5706/kypiopt/public_html/vendor/symfony/http-kernel/HttpKernel.php(151): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#15 /home/s/savage5706/kypiopt/public_html/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#16 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/StackMiddleware/Session.php(57): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#17 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(47): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#18 /home/s/savage5706/kypiopt/public_html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#19 /home/s/savage5706/kypiopt/public_html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#20 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(47): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#21 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(52): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#22 /home/s/savage5706/kypiopt/public_html/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#23 /home/s/savage5706/kypiopt/public_html/web/core/lib/Drupal/Core/DrupalKernel.php(708): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#24 /home/s/savage5706/kypiopt/public_html/web/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#25 {main}

I do not know what's the problem. Perhaps the matter is in the commerce_simple_stock module. Anyway, when I try to repeat order, I get the message:
"The website encountered an unexpected error. Please try again later."

best regards,
Savage