This article covers how to fix 330 Content Decoding Failed Nagios browser error. Basically, this error occurs when an HTTP request's headers claim that the content is gzip encoded, but it is not.
To fix this error:
The Apache web server requires zlib.output_compression to be configured to On in the /etc/php.ini file.
Execute the following command to open the file in vi:
When using the vi editor, to make changes press i on the keyboard first to enter insert mode.
Press Esc to exit insert mode.
To locate the line zlib.output_compression = type the following:
This should take you directly to the line. Change the setting to On:
zlib.output_compression = On
When you have finished, save the changes in vi by typing:
and press Enter.
The last step is to restart the Apache service using one of the commands below:
RHEL 7 + | CentOS 7 + | Oracle Linux 7 +
$ systemctl restart httpd.service
Debian | Ubuntu 16/18/20
$ systemctl restart apache2.service
After the service has restarted the problem should no longer occur.