Following is the error encounter after disabling the cache in Drupal
The website encountered an unexpected error. Please try again later.
Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException: You have requested a non-existent service “cache.backend.null”. Did you mean one of these: “cache.backend.apcu”, “cache.backend.php”, “cache.backend.memory”? in Drupal\Component\DependencyInjection\Container->get() (line 161 of core\lib\Drupal\Component\DependencyInjection\Container.php).
Drupal\Component\DependencyInjection\Container->get('cache.backend.null') Drupal\Core\Cache\CacheFactory->get('render') call_user_func_array(Array, Array) Drupal\Component\DependencyInjection\Container->createService(Array, 'cache.render') Drupal\Component\DependencyInjection\Container->get('cache.render', 1) Drupal\Component\DependencyInjection\Container->resolveServicesAndParameters(Object) Drupal\Component\DependencyInjection\Container->createService(Array, 'http_middleware.page_cache') Drupal\Component\DependencyInjection\Container->get('http_middleware.page_cache', 1) Drupal\Component\DependencyInjection\Container->resolveServicesAndParameters(Object) Drupal\Component\DependencyInjection\Container->createService(Array, 'http_middleware.reverse_proxy') Drupal\Component\DependencyInjection\Container->get('http_middleware.reverse_proxy', 1) Drupal\Component\DependencyInjection\Container->resolveServicesAndParameters(Object) Drupal\Component\DependencyInjection\Container->createService(Array, 'http_middleware.negotiation') Drupal\Component\DependencyInjection\Container->get('http_middleware.negotiation', 1) Drupal\Component\DependencyInjection\Container->resolveServicesAndParameters(Object) Drupal\Component\DependencyInjection\Container->createService(Array, 'http_kernel') Drupal\Component\DependencyInjection\Container->get('http_kernel') Drupal\Core\DrupalKernel->getHttpKernel() Drupal\Core\DrupalKernel->handle(Object)
Solution:
Run http://www.example.com/rebuild.php then reload and it works again. Researching why is this. Please let me know if found anything.