Hi,
thx for reply. I wasn't sure where is a problem - so i didn't exactly know what I want : ).
Now I'm sure that I want to fix a problem that error page is shown (after successful registration) and I'll try your solution.
[EDITED few minutes later]
Hmmmm i don't see where can i change page to redirect after registration??
Here is answer from easy-profile support:
Easy Profile extends Joomla user management (not replace), so registration process and page is the same of Joomla with many improvements. After Registration Joomla redirect you to a blank page with success message and instructions to activate account.