Blank Screen with CodeIgniter

问题:

I've just moved a site across to a production server, and a once working CodeIgniter installation now returns a blank screen. I believe it is due to whitespace, but how are you supposed to find something like that?

回答1:

Things to check:

• Inside config.php, make sure your $config['base_url'] is set properly
• Were you able to copy your .htaccess as well?
• Do you have the same PHP versions in both machines? If your answer is yes, i'll ask you again: Are you sure?
• What is the value of your $db['default']['hostname']?
• Do you have the same database setup in your local and production server? There could be differences with the hostname, username, password and database name

Other things you can do:

• Set $db['default']['db_debug'] to TRUE
• Deploy a fresh CodeIgniter installation in your production server and check if you can see something
• If you still see a blank page, deploy a single PHP file with text in it and tell us what you see

回答2:

The issue may be due to missing the php module 'mysqli'. This is the driver to your calling on the database. I would check that with:

php -i | grep mysqli

php -m

回答3:

I experienced the same issue and I solved it by setting my log-folder to writable. It seems, that if you turn on logging, and your log-folder on your server is not writable, CodeIgniter just shows you an empty page.

回答4:

Load your url helper when you create a function, eg:

visibility function_name () 
{
    $this->load->helper('url');

}

It will show you errors or a view you loaded.

回答5:

I have simillar problem. I try all possible way that people wrote. But no one work for me. But, finnaly i found that my index.php is not complete when transfer to server via ftp. So, if anyone still can't solve white screen of death may your index.php is not complete.

回答6:

If you've moved to a new server ensure the server has PHP-5 installed on it. The reason why the screen is blank is because the server cannot render PHP yet.

Type this line in and restart after:

sudo apt-get install php5 libapache2-mod-php5

To restart:

sudo service apache2 restart

This is of course assuming you have access to the server via an SSH client with admin rights.

best of luck, Niall

回答7:

Declare this somewhere in your /index.php file:

function exception_handler($exception) {
    echo "Uncaught exception: " . $exception->getMessage();
}

set_exception_handler('exception_handler');

It seems CodeIgniter (v2?) only handles exceptions that are derived from CI_Exception, so any uncaught exceptions (from third party libraries, etc) are not handled.