Twentyfifteen & polylang translations

Hi everybody..

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, categories, tags) but not the menu and widgets, so these are always displayed in default language.

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.

The url of my site is https://www.ub.edu/casosint

Wordpress and theme lastest version
Polylang 2.0.7

Please I really need some orientation. I am really stucked at this point and I’ve to have it ready for next week.

Thank you for reading me!