Troubleshooting Missing CSS/JS in the Control Panel

You’re trying to install Craft for the first time and you notice that no CSS or JS is being loaded in the installer. Or maybe you view your browser’s inspector and the response to the CSS/JS files are all garbled.

Chances are you have zlib.output_compression enabled in your php.ini file and you need to disable it. This is most likely related to this PHP bug report.

Even if you’re not getting garbled CSS/JS in the response, you might see this error as in your browser or in the response for the CSS/JS:

Failed to delete buffer zlib output compression

The fix for that error is the same.

Note that you will probably have to restart your web server for any changes to the php.ini file to take affect.