Fatal error: Call to undefined method Zend_CodeGenerator_Php_File

I get the following error returned when clicking edit or add new customer within the admin panel. customers–> manage customers –> “edit” or “add new customer”

Fatal error: Call to undefined method Zend_CodeGenerator_Php_File::shutdown() in /var/app/current/lib/Zend/Log.php on line 366

Lines 363 to 367 highlighted below

{
        /** @var Zend_Log_Writer_Abstract $writer */
        foreach($this->_writers as $writer) {
            $writer->shutdown();
        }

How do I fix this?