Problem
In WordPress, after installed WP Super Cache plugin, the system cannot be started successfully. The page shows
HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.
Reason
The memory size for running this plugin is not enough.
Solution
Increase the PHP memory for WordPress. In wp-config.php, insert below line
define('WP_MEMORY_LIMIT', '96M');
before the line
define('WP_CACHE', true);
If 96M is still not enough, can try increasing more.