Sometimes suddenly we found internal server error on our website.The main resons for this error are

1. .htaccess file can be corrupted.
2. corrupt wordpress installation.
3. conflicting plugin.
4. PHP memory limits.

We can find the exact error by checking to error log,we can do so by:

Open up your wp-config.php file, and locate the following line of code:

define(‘WP_DEBUG’, false);

And change it to:

define(‘WP_DEBUG’, true); as some shared hosting has by default settings of false wp_debug mode.

How to remove error:

1. if error is caused by htaccess file,then locate the file form filezilla and rename this file->refersh the site
-> Now go to Settings–>Permalinks in your WP admin panel and re-save the settings.New .htaccess file will be created.

2. If error is caused due to memory limit ,than you can increase php memory.

3. If error is due to plugins,then deactivate all plugins and activate them one by one to find the cause.

4. If all above fail, then we need to re-upload the wp-admin and wp-includes directories.