Drupal - Fatal error sessionhandler

Question

I am receiving following errors when I try to access pages and the site becomes inaccessible(error 500).

PHP Fatal error: Class Drupal\\Core\\Database\\Statement contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (Drupal\\Core\\Database\\StatementInterface::fetchObject) in /projects/core/lib/Drupal/Core/Database/Statement.php on line 16

PHP Fatal error: Class Drupal\\Core\\Session\\SessionHandler contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (SessionHandlerInterface::read) in /projects/core/lib/Drupal/Core/Session/SessionHandler.php on line 15

Restarting server will solve the issue for a limited time. Just found it was a memory issue. changed the memory_limit to 128, 256 and 512 but really seems to have happen randomly while browsing my website

Apache/2.4.29, PHP 7.0.26

Answer 1

Hey just need to delete cache or run drupal cron. for more details, please go to following the link.

https://www.drupal.org/project/drupal/issues/2668564

Hope it will useful for you.