Activating premium version after trial

Hello,

I just updated to premium version after the trial and I get this error message when i click on the link to activate my account :

Fatal error: Uncaught TypeError: Argument 1 passed to Freemius::_encrypt_entity() must be an instance of FS_Entity, null given, called in /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php on line 8865 and defined in /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php:7052 Stack trace: #0 /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php(8865): Freemius::_encrypt_entity(NULL) #1 /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php(9018): Freemius->_store_plans(false) #2 /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php(7254): Freemius->_store_account() #3 /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php(7534): Freemius->_set_account(Object(FS_User), Object(FS_Site)) #4 /var/www/b in /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php on line 7052

I also get this messages :

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; EvcalWidget_SC has a deprecated constructor in /var/www/blog/wp-content/plugins/eventON/includes/class-evo-widget-main.php on line 292

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; EvcalWidget_next_month has a deprecated constructor in /var/www/blog/wp-content/plugins/eventON/includes/class-evo-widget-main.php on line 378

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; EvcalWidget_three has a deprecated constructor in /var/www/blog/wp-content/plugins/eventON/includes/class-evo-widget-main.php on line 448

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; EvcalWidget_four has a deprecated constructor in /var/www/blog/wp-content/plugins/eventON/includes/class-evo-widget-main.php on line 518

Notice: Undefined property: stdClass::$plan_id in /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/entities/class-fs-site.php on line 107

Warning: Invalid argument supplied for foreach() in /var/www/blog/wp-content/plugins/featured-images-for-rss-feeds/includes/freemius/includes/class-freemius.php on line 5793

The page I need help with: [log in to see the link]