15.7. Fixing the problem of empty pages shown after saving the settings

Your server may have a request filter that checks the content of the request, and it may find a few settings in General Settings Page unsafe. You can delete the values of HTTP User Agent and HTTP Accept settings under Advanced Tab of General Settings Page. If the problem is in Site Settings Page, then you can delete the values under Settings Tab of Site Settings Page. You don’t need to worry about these settings, since the default values will be used when they are empty.

Alternatively, you can ask your server’s support team to remove that filter or allow your site to bypass that filter.