Fatal error: Internal Zend error - Missing class information ...
This often occurs in PHP versions 5.3 or 5.4 with the APC extension enabled. As the message suggests, this is an internal error deep inside PHP. Since PHP 5.3 and 5.4 have reached end-of-life, this error will never be fixed by the PHP developers.
Below we list a few solutions to get past this error. Your hosting provider should be able to assist you with any of these tasks. We recommend that you send them a link to this page so they can understand the situation.