Error: 0 - Layout Path Not Found

When I try my Paypal form - I get that error in fronted when I submit, You have an idea?
Error: 0 - Layout Path Not Found

The url with the error is something like http://my_site.com/component/pmform/?Itemid=

Seem something is missing ?

On Firebug console, the error is:

Something strange here. Please :

1. Submit a support ticket sending us super admin account of your site

2. Send us the link to the form page

We are going to check to see what's wrong and get it sorted for you

Regards,

Tuan