Hi,
Your error is maybe due to our server configuration more than the template. It's just a warning and not a bug or an error.
Currently this type of error not appear.
Look into php.ini file at parameter "error_reporting" an turn to this
error_reporting = E_ALL & ~E_NOTICE
It show all errors, except for notices, your current error.
Else if you want to hide all errors warning, turn parameter "display_errors" to OFF
