"Could not write to the configuration file"

Why it happens

Joomla protects configuration.php by making it read-only (444) after saving. If the file is read-only and the server can't change that, saving Global Configuration fails.

Fix it

1. In your file manager or FTP, set configuration.php to 644.
2. Save Global Configuration again.
3. Joomla sets the file back to read-only after saving. If it can't, set it back to 444 yourself.

Good to know

• If 644 isn't enough, the file belongs to a different user than the web server. Ask your host to fix the ownership instead of using 777.