Here are some common installation problems, and suggested workarounds.

How do I know if my install is working?

From the command line, at your project root:

> php spark serve

http://localhost:8080 in your browser should then show the default welcome page:

CodeIgniter4 Welcome

I have to include index.php in my URL

If a URL like /mypage/find/apple doesn’t work, but the similar URL /index.php/mypage/find/apple does, that sounds like your .htaccess rules (for Apache) are not set up properly, or the mod_rewrite extension in Apache’s httpd.conf is commented out.

Only the default page loads

If you find that no matter what you put in your URL only your default page is loading, it might be that your server does not support the REQUEST_URI variable needed to serve search-engine friendly URLs. As a first step, open your app/Config/App.php file and look for the URI Protocol information. It will recommend that you try a couple of alternate settings. If it still doesn’t work after you’ve tried this you’ll need to force CodeIgniter to add a question mark to your URLs. To do this open your app/Config/App.php file and change this:

public $indexPage = 'index.php';

To this:

public $indexPage = 'index.php?';

The tutorial gives 404 errors everywhere :(

You can’t follow the tutorial using PHP’s built-in web server. It doesn’t process the .htaccess file needed to route requests properly.

The solution: use Apache to serve your site, or else the built-in CodeIgniter equivalent, php spark serve from your project root.

What’s with an unhelpful “Whoops!” page?

You find that your app is displaying a page with “Whoops!” and then the text line “We seem to have hit a snag. Please try again later…”.

That is a sign that you are in production mode and have hit an unrecoverable error, which we don’t want to show to the viewer of the webapp, for better security.

You can see the error in the debug toolbar display by setting your environment to “development” (in .env), and reloading the page.

Don’t forget to reset the environment to “production” once you fix the problem!

CodeIgniter Error Logs

CodeIgniter logs error messages, according to the settings in app/Config/Logger.php.

You can adjust the error threshold to see more or fewer messages.

The default configuration has daily log files stored in writable/logs. It would be a good idea to check them if things aren’t working the way you expect!