Fatal error: Allowed memory size of 33554432 bytes exhausted

Problem Description
In the wordpress dashboard Plugins, Incoming Links section does not load and loading fails with message,
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 1966080 bytes) in /home/nextlew4/public_html/arju-on-it.com/wp-includes/class-simplepie.php on line 5409

Also, whenever you try to upgrade any plugin it fails with message,
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 2350382 bytes) in /home/nextlew4/public_html/arju-on-it.com/wp-includes/http.php on line 1365

Cause of the Problem
From the wordpress release of 2.5, within wp-settings.php file there is parameter WP_MEMORY_LIMIT which allows you to specify the maximum amount of memory that can be consumed by PHP. The default value for WP_MEMORY_LIMIT is limit to 32MB. So by default, WordPress will attempt to increase memory allocated to PHP to 32MB (you can find this code at beginning of wp-settings.php).

Note that, this setting imposes memory limit to usage memory of PHP only for WordPress, not other applications.

Solution of the Problem
If wordpress PHP needs more memory than the value set inside wp-settings.php you will receive a message such as "Allowed memory size of xxxxxx bytes exhausted".

So the setting in wp-config.php should reflect something higher than 32MB.

You will find the wp-config.php file under wordpress home installation directory. If you open the file you will see the following lines at the beginning of the file.

if ( !defined('WP_MEMORY_LIMIT') )
define('WP_MEMORY_LIMIT', '32M');

Increase the limit to somewhere bigger value. For example to increase PHP Memory to 64MB

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

Increase PHP Memory size to 100MB
define('WP_MEMORY_LIMIT', '100M');


Please note that, this setting may not work if your host does not allow for increasing the PHP memory limit. If after increasing limit from wp-settings.php you still get "Fatal error: Allowed memory size of 33554432 bytes exhausted" contact your host to increase the PHP memory limit. Note that many hosts set the PHP limit at 8MB.

Related Documents
http://arjudba.blogspot.com/2010/01/how-to-add-logo-to-wordpress-site.html
http://arjudba.blogspot.com/2010/01/how-to-transfer-wordpress-site-to-new.html
http://arjudba.blogspot.com/2010/01/introducing-wordpress-theme.html
http://arjudba.blogspot.com/2010/01/how-to-install-wordpress.html