I get the following error returned when clicking Edit or Add New Customer in Admin >> 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?

We have not experienced this error before and the code within the files indicated in the error has not changed from prior application versions.