Can't save Joomla 3 global configuration

Question

I have a Joomla 3.4.4 website online and I can't change the global configuration settings. I'm super user but any changes I made on Global Configuration area doesn't change anything after save. This is what I've done so far:

• Add 644, 666 and 777 permissions to configuration.php file (on Filezilla). No success;
• Clear browser cache. No success;
• Add JHtml::_('behavior.framework', true); on Isis index.php file. No success;
• Update Joomla from 3.4.1 to 3.4.4. No success;
• Purge cache and update database. No success;
• Remove "from email" field. No success;
• Replace the media/js files from a fresh install. No success;
• Check JS errors on page. There's no error at all.

I can't reinstall the website because it's already online and there are many users using it.

Here is my global configuration screen:

More information: The website is working fine, even in backend area, except the global configuration area. It's may caused by some plugin, but I disabled all plugins that i'm not using. The theme is Isis in backend and Aura in frontend. My host is Hostagtor.

Answer 1

In some cases, the problem is caused by an inflated ACL. If you have too many usergroups on the Joomla website, then you can have this problem. The reason why is because each one of these usergroups will create several fields on the configuration settings form, eventually causing the number of fields on your configuration settings form to exceed the number of allowed fields in any form. Increasing the max_input_vars should fix the problem. See here for full details about this problem.

Answer 2

The file permission of 644 will suffice. The reason you are facing the issue is due to ownership of the configuration file.

If you are using Apache, the following command to change ownership of the file will resolve the problem.

sudo chown www-data:www-data configuration.php