Error registration with Event plugin

I have the following problem with the plugin Event.
If I try to register for an event using the plugin I get the following error:

Not Found

The requested URL / component / index.php was not found on this server.

Help me please.... :ohmy:

Joomla 1.5.26
Last version of Event booking

Hi

Please submit a support ticket sending me administrator and FTP account of your site so that I can check and solve the issue for you. Maybe there is something special on your site / your server causing this issue .

Tuan