hi everybody since tonight i have a new liberkey interface and i want the old but in the tools menu don't apper the button to confirm the change. i have the 5.5 version. thank

What do you mean by "the old" ? There is only two interfaces (since Liberkey 5.0), one is accessed with a right click on the tray icon, the other is accessed with a left click, try it and let us know.

P.S : you can switch the right/left click behavior (and also the corresponding keyboard shortcuts) from the options in the "User interface" part of the liberkey tools -> configuration window.