Fatal error: Allowed memory size…

Hello everyone

After the istallation i added a theme and started to add plug ins. I don’t know why now, I can’t anymore access to my dashboard. When I click “customize” I have the following error (I modified the wp-config.php file whit debug set as true)

Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 81 bytes) in /hsphere/local/home/bbbmaoh/capsulecoproduction.com/wp-includes/class-wp-post.php on line 240 ( i put the row in Italic).

At line 240 the file class-wp-post.php on line 240 I have the following text:
public function __construct( $post ) {
foreach ( get_object_vars( $post ) as $key => $value )
$this->$key = $value;
}

Thanks for anyone who will help me!