Error in the custom plugin, after upgrade the mautic

Hello,
I have upgraded the mautic to 5.1, in older version I have developed a custom plugin. But after upgraded the mautic, the custom plugin not working.
In the custom plugin, I have created external menu, when I clicked on the link I am getting “Inernal Server Error”, I checked the logs and found following error.

mautic.CRITICAL: Uncaught PHP Exception LogicException: ““MauticPlugin\MauticVtigerContactReplicatorBundle\Controller\HomeController” has no container set, did you forget to define it as a service subscriber?” at /var/www/vhosts/new-master-dev.ballistixmail.com/www/vendor/symfony/framework-bundle/Controller/ControllerResolver.php line 37 {“exception”:“[object] (LogicException(code: 0): "MauticPlugin\MauticVtigerContactReplicatorBundle\Controller\HomeController" has no container set, did you forget to define it as a service subscriber? at /var/www/vhosts/new-master-dev.ballistixmail.com/www/vendor/symfony/framework-bundle/Controller/ControllerResolver.php:37)”} {“hostname”:“mautic-dev02”,“pid”:2622589}