Maximum upload file size – tried everything!

I’ve added the following to .htaccess:

php_value upload_max_filesize 64M
php_value post_max_size 64M
php_value max_execution_time 300
php_value max_input_time 300

wp-config:

@ini_set( 'upload_max_size' , '64M' );
@ini_set( 'upload_max_filesize' , '64M' );
@ini_set( 'post_max_size', '64M');

functions.php:

@ini_set( 'upload_max_size' , '64M' );
@ini_set( 'post_max_size', '64M' );
@ini_set( 'max_execution_time', '300' );

I also tried creating a php.ini in the root (and tried moving it to the admin folder, and tried renaming it ‘php5.ini’) and added this:

upload_max_filesize = 64M
post_max_size = 64M
max_execution_time = 300

None of the above worked, the only thing that made any difference was adding this to the media.php file:

$u_bytes = wp_convert_hr_to_bytes( '128MB' );
$p_bytes = wp_convert_hr_to_bytes( '128MB' );

But all this seemed to change was the text ‘Maximum upload file size: 128 MB.’ is allowed the import to start, but it didn’t allow the upload, ‘http error’.

I have the following installed, and I’m using Paradise Cove by ThemeFuse
WordPress 4.3.1
All In One WP Security
Sucuri Security