Wp Dev dashboard plugin error

WpmuDev dashboard plugin is throwing a fatal error. Only on specific admin page. Always When clicked on Appearence->customize. I have already edited wp-config file with Define Max memoery limit to 256M. But still error exist. Does this have any security issue ?

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 281520 bytes) in /home/youfeedx/public_html/wp-content/plugins/wpmudev-updates/includes/class-wpmudev-dashboard-site.php on line 1097