Error message

Notice: Trying to access array offset on value of type null in donationdrive_commerce_product_variation_view_alter() (line 303 of /mnt/shared/northshorehumane/modules/custom_modules/donationdrive/donationdrive.module).

donationdrive_commerce_product_variation_view_alter(Array, Object, Object) (Line: 539)
Drupal\Core\Extension\ModuleHandler->alter('commerce_product_variation_view', Array, Object, Object) (Line: 305)
Drupal\Core\Entity\EntityViewBuilder->buildMultiple(Array) (Line: 239)
Drupal\Core\Entity\EntityViewBuilder->build(Array)
call_user_func(Array, Array) (Line: 37)
Drupal\commerce_product\ProductVariationFieldRenderer->renderFields(Object, 'full') (Line: 96)
Drupal\commerce_product\ProductViewBuilder->alterBuild(Array, Object, Object, 'full') (Line: 292)
Drupal\Core\Entity\EntityViewBuilder->buildMultiple(Array) (Line: 239)
Drupal\Core\Entity\EntityViewBuilder->build(Array)
call_user_func_array(Array, Array) (Line: 101)
Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_render callbacks must be methods of a class that implements \Drupal\Core\Security\TrustedCallbackInterface or be an anonymous function. The callback was %s. See https://www.drupal.org/node/2966725', 'exception', 'Drupal\Core\Render\Element\RenderCallbackInterface') (Line: 786)
Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array) (Line: 377)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 201)
Drupal\Core\Render\Renderer->render(Array, ) (Line: 241)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 578)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 242)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 132)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object)
call_user_func(Array, Object, 'kernel.view', Object) (Line: 142)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object, 'kernel.view') (Line: 163)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 80)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 46)
Drupal\redirect_after_login\RedirectMiddleware->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 191)
Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 128)
Drupal\page_cache\StackMiddleware\PageCache->lookup(Object, 1, 1) (Line: 82)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 717)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)