Fatal error: Allowed memory size of 67108864 bytes exhausted

Just updated the default-constants.php file just as it says in the link : https://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP

And I'm still getting the same error message.

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 435729 bytes) in /home/aimandamplfiy/public_html/wp-includes/functions.php on line 354

What is the next step on trouble shooting this?