500 server error on clear cache I am facing a pretty strange problem. I have installed Drupal 7 on my site. Whenever I install a module and tries to access the module's configure page after enabling the module, it leads me to simply /admin/config page without showing the option for that particular module configuration.

sometimes when I do a clear cache the problem gets resolved and then I can access the module's config page. but sometime after installing a module, clear cache gives Internal Server Error 500 .. also I tried to flush the cache manually by making a php file into / directory with the following code:

&lt;?php
include_once './includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
drupal_flush_all_caches();
?&gt;


but this also gives Error 500.

When I disable the installed module, clear cache works as usual...
please help me.
As directed by aerozeppelin I got the following error: 


  Fatal error: Allowed memory size of 50331648 bytes exhausted (tried to allocate 4096 bytes) in /home/htdocs/includes/database/query.inc on line 1857


So increasing the PHP memory limit is the cure; this link is useful for that.