Good day,
I have upgraded from OJS 3.3.0.14 to 3.4.0.3 and when clicking on any page I get the following errors in my log files.
Exception: Plugin announcementMailFix expected to inherit from AnnouncementMailFixPlugin, actual type NULL in /var/www/html/lib/pkp/classes/plugins/PluginRegistry.php:203\nStack trace:\n#0 /var/www/html/lib/pkp/classes/plugins/PluginRegistry.php(219): PKP\plugins\PluginRegistry::_instantiatePlugin()\n#1 /var/www/html/lib/pkp/classes/plugins/PluginRegistry.php(112): PKP\plugins\PluginRegistry::_loadFromDatabase()\n#2 /var/www/html/lib/pkp/classes/core/Dispatcher.php(155): PKP\plugins\PluginRegistry::loadCategory()\n#3 /var/www/html/lib/pkp/classes/core/PKPApplication.php(387): PKP\core\Dispatcher->dispatch()\n#4 /var/www/html/index.php(21): PKP\core\PKPApplication->execute()\n#5