Menu&widgets doesn’t switch language

My information:
Your permalinks settings: entry name
Static front page: yes
Polylang 2.0.7 settings: all default settings
site url: http://www.ub.edu/casosint

Problem: I added manually a language switcher in my header and customize it with css. In some point the switcher stopped working and now it only translates the content (pages, posts, etc) but not the menu and widgets. So these to are always displayed in spanish.

I added the following in header.php, maybe here’s the problem but since i’m not expert I can’t understand what’s happening:
<?php pll_the_languages(array('show_flags'=>0, 'show_names'=>1)); ?>

Now if I delete this I just get some kind of error and nothing shows up.

Things I tried:
– Deactivate Polylang and create two menus in your theme. Assign the second menu which you have created and check your frontend: what happens is that no content shows up, neither the static page.
– Deactivte plugins to see incompatibilities, nothing seems to be troubling.
– Checked my menus catalan/spanish, also the widgets. They are correctly configured to be shown in correspondent languages.

Thank you for your support.