Joomla error: 'Illegal variable _files or _env or _get or _post or _cookie or _server or _session or globals passed to script'

Question

I am getting this error in Joomla:

Illegal variable `_files` or `_env` or `_get` or `_post` or `_cookie`
or `_server` or `_session` or `globals` passed to script         


        

Answer 1

It's not an error PHP generates, it's an error that seems to belong to Joomla!. I found this page after 20 seconds of Googling for "Illegal variable".