Memory problem

Hi, i’ve found a next Problem. I run into an 500 Server Error If i try to save a Menü. WP Shows the following Error:

Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 20480 bytes) in /home/www/wp-content/plugins/xa-woocommerce-memberships/includes/class-xa-woocommerce-user-memberships.php on line 15

Of course, If i deactivate the Plugin, No Probleme to save the Menü (a huge one).

Regards, Frank