Not able to save settings for CB Paid Subscriptions: General plugin settings

We are getting the following error
Forbidden

You don't have permission to access /administrator/index.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

when I try to save the settings for CB Paid Subscriptions: General plugin settings.

Any ideas?

Peace

A Human

This is often due to input limits or possibly a mod_security issue. Please check within Site > System Information > PHP Information that "max_input_nesting_level" and "max_input_time" have reasonably high values (60 or greater seams to be ok). Please enable debug mode and maximum error reporting in Joomla global configuration then re-test the issue and review your server error logs to see if the error further exposes.