Fatal Error using CSV add

I keep geting the following error message:

Fatal error: Cannot access empty property in /home3/petermon/public_html/wp-content/plugins/add-multiple-users/functions/commonfn.php on line 263

I have tried reloading plug-in; tried using different approches and settings, but keep getting this message.

Can anyone help me pls?

http://wordpress.org/extend/plugins/add-multiple-users/