Can't load phpMyAdmin any longer

[DeveloperMcD]

I get this error:

PHP Fatal error:  main(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "PMA\\libraries\\ThemeManager" of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition  in /usr/local/apache/htdocs/phpMyAdmin/libraries/common.inc.php on line 700