Go to your ftp and find either error_logs or ask your host for any server error logs also any errors will be emailed to the email you have set in the config file if you have any errors or warnings post that info here
If a error or you have a problem from a plugin you need to ask in the topic for that plugin for support you can also try disabling plugins via your config file to do that follow this.
To temporarily disable the plugin system, edit includes/config.php and add this line right under <?php
PHP Code:
define('DISABLE_HOOKS', true);
To enable plugins again just comment out the line
PHP Code:
//define('DISABLE_HOOKS', true);
Use
notepad++ to edit any files