Error when trying to activate MPG Pro Plan

Error:

ERROR WHEN TRYING TO ACTIVATE PREMIUM
Fatal error: Cannot redeclare class MPG_CoreModel in /home/auctipa3/public_html/getacrashreport/wp-content/plugins/multi-pages-plugin-premium/models/CoreModel.php on line 4

Solution:

Please make sure to fully delete the free version before installing the MPG Pro plan.