Oh, thank you very much!!
This theme doesnt have any other plugins. So before polylang I have all deactive.
http://themeforest.net/item/momentum-simple-creative-one-page-theme/8056483
a first Polylang installation.
But a first was ok to “settings / add a new language ” after choose my language and click on the button “Add a new” – after this everyting was blank. Then I must delete folder polylang on ftp.
Next instalation was stop after activate.
