I just ran into this problem, after setting the memory_limit in php.ini, wp-config and htaccess and confirming the values were in effect on the info.php page without any change in the error message I added
ini_set('memory_limit', '4096M');
to the top of my functions.php file within my theme and it resolved the issue. Not sure if this is a Bitnami bug or what, but the php.ini file settings were being overwritten somewhere on the Wordpress module level.
Note: I am on a Bitnami LAMP stack configuration with multiple Wordpress modules.