Fatal error: Allowed memory size

I tried this solution :
Create a file called php.ini in the root of your site (if you are using a hosted addon domain, this must be in the subdirectory of that site)
In php.ini, enter a line that says
memory_limit = 64MB
In your site’s .htaccess (being a WordPress blog, I’m assuming there is one), enter the following line
SetEnv PHPRC /<unix path to the directory where php.ini is>/
(keep the slashes)
Edit wp-config.php and enter the following line
define(‘WP_MEMORY_LIMIT’, ’64M’);
Upload the new files to the server

But i’v got a 500 error with the Htaccess file.

Does someone ‘got an idea ?
I ve still have a fatal error to connect to the dashboard

Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 7680 bytes) in /home/www/rosa/www/wp-admin/includes/template.php on line 3417

You should contact your hosting company, and ask them the proper procedure for increasing PHP’s memory. It can vary from host to host, and it should be an easy question for them to answer.

You can also try simply adding this:

define('WP_MEMORY_LIMIT', '64M');

To wp-config.php.