wp-invoice error (wp-settings.php on line 473)

I just tried to install a new plugin (wp-invoice) and when I try to activate it, I get the following error message. Additonally if I try to install the plugin from c-panel, the plugin does not show up in the wp admin plugin section. Thank you for any assistance you can provide.

I haven’t had problems with any other plugins and have tried installing the plugin on a blank WP install with no other plugins or themes running in case there was an issue there.

Ben

Warning: include_once(/home1/vidamiap/public_html/test/wp-content/plugins/wp-invoice/) [function.include-once]: failed to open stream: Success in /home1/vidamiap/public_html/test/wp-settings.php on line 473

Warning: include_once() [function.include]: Failed opening '/home1/vidamiap/public_html/test/wp-content/plugins/wp-invoice/' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home1/vidamiap/public_html/test/wp-settings.php on line 473