Problem
I'm trying to configure my search API server, however when I click on the menu item (Configuration > Search and Metadata > Search API), I get the lovely error message "The website encountered an unexpected error. Please try again later." The issue I'm having is it works fine on my local environment, but when I push it up to the dev server I'm getting the issue.
Here is the error message I'm getting.
Error: Class 'Drupal\search_api_solr_legacy\Plugin\SolrConnector\Solr36Connector' not found in include() (line 23 of /code/modules/contrib/search_api_pantheon/src/Plugin/SolrConnector/PantheonSolrConnector.php)
#0 /code/vendor/composer/ClassLoader.php(571): include()
#1 /code/vendor/composer/ClassLoader.php(428): Composer\Autoload\includeFile('/code/modules/c...')
#2 [internal function]: Composer\Autoload\ClassLoader->loadClass('Drupal\\search_a...')
#3 [internal function]: spl_autoload_call('Drupal\\search_a...')
#4 /code/core/lib/Drupal/Component/Plugin/Factory/DefaultFactory.php(96): class_exists('Drupal\\search_a...')
#5 /code/core/lib/Drupal/Core/Plugin/Factory/ContainerFactory.php(17): Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass('pantheon', Array, 'Drupal\\search_a...')
#6 /code/core/lib/Drupal/Component/Plugin/PluginManagerBase.php(83): Drupal\Core\Plugin\Factory\ContainerFactory->createInstance('pantheon', Array)
#7 /code/modules/contrib/search_api_solr/src/Plugin/search_api/backend/SearchApiSolrBackend.php(596): Drupal\Component\Plugin\PluginManagerBase->createInstance('pantheon', Array)
#8 /code/modules/contrib/search_api_solr/src/Plugin/search_api/backend/SearchApiSolrBackend.php(1452): Drupal\search_api_solr\Plugin\search_api\backend\SearchApiSolrBackend->getSolrConnector()
#9 /code/modules/contrib/search_api/src/Entity/Server.php(473): Drupal\search_api_solr\Plugin\search_api\backend\SearchApiSolrBackend->search(Object(Drupal\search_api\Query\Query))
#10 /code/modules/contrib/search_api/src/Query/Query.php(539): Drupal\search_api\Entity\Server->search(Object(Drupal\search_api\Query\Query))
#11 /code/modules/contrib/search_api/src/Plugin/views/query/SearchApiQuery.php(581): Drupal\search_api\Query\Query->execute()
#12 /code/core/modules/views/src/ViewExecutable.php(1426): Drupal\search_api\Plugin\views\query\SearchApiQuery->execute(Object(Drupal\views\ViewExecutable))
#13 /code/core/modules/views/src/ViewExecutable.php(1454): Drupal\views\ViewExecutable->execute(NULL)
#14 /code/core/modules/views/src/Plugin/views/display/Page.php(199): Drupal\views\ViewExecutable->render()
#15 /code/core/modules/views/src/ViewExecutable.php(1630): Drupal\views\Plugin\views\display\Page->execute()
#16 /code/core/modules/views/src/Element/View.php(81): Drupal\views\ViewExecutable->executeDisplay('page_search', Array)
#17 [internal function]: Drupal\views\Element\View::preRenderViewElement(Array)
#18 /code/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php(101): call_user_func_array(Array, Array)
#19 /code/core/lib/Drupal/Core/Render/Renderer.php(772): Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_ren...', 'exception', 'Drupal\\Core\\Ren...')
#20 /code/core/lib/Drupal/Core/Render/Renderer.php(363): Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array)
#21 /code/core/lib/Drupal/Core/Render/Renderer.php(201): Drupal\Core\Render\Renderer->doRender(Array, false)
#22 /code/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(241): Drupal\Core\Render\Renderer->render(Array, false)
#23 /code/core/lib/Drupal/Core/Render/Renderer.php(564): Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}()
#24 /code/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(242): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#25 /code/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(132): Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#26 /code/core/lib/Drupal/Core/EventSubscriber/MainContentViewSubscriber.php(90): Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#27 [internal function]: Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#28 /code/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(142): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#29 /code/vendor/symfony/http-kernel/HttpKernel.php(163): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view')
#30 /code/vendor/symfony/http-kernel/HttpKernel.php(80): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#31 /code/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#32 /code/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#33 /code/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#34 /code/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#35 /code/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#36 /code/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#37 /code/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#38 /code/core/lib/Drupal/Core/DrupalKernel.php(708): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#39 /code/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#40 {main}
Any advice or help would be appreciated. If more information is needed let me know.