Class 'Shopware_Components_LicensePersister' not found


I have purchased one plguins “Anrede entfernen” that is paid plugins. Now i am trying to install and import license than i am getting below error.

Fatal error: Class ‘Shopware_Components_LicensePersister’ not found in /var/www/virtual/ on line 82

Do anyone have a solution for this?

Thanks in advance.

This post is missing a lot of information that might be useful to help you.

Which Shopware version do you use?
Is the license manager installed and activated?

In order to use a plugin which needs a license, you need the license manager in your shop: 
Shopware License Manager | System | Administration | Extensions | Shopware Community Store

The error message indicates, that there is an issue with the license manager. Please check this first.