Trouble changing interface language

Hi. I got LibOffice in my Lubuntu current version, set to Venezuela Spanish. After update to version via OS five days ago, interface language was changed to English. I went to Tools->Options->Language. Under Interface language, English is the only option available. Rest of settings work fine, document language, decimal setting, ortographic, etc are working fine in Venezuela Spanish.
Any idea how to solve this?
Thanks in advance for any help you may give

… to version via OS …

This is not the most recent release (4.3.3) and may not be downloaded from the official site. As Lubuntu emphasises “lean” solutions they may have packaged LibO extra lean. You may try uninstalling and reinstalling LibO from a deb package from the official source. A “virgin install” should offer adding any selection of languages for the UI you can later choose from.
Please be aware: I don’t know anything about Lubuntu specifics (LXDE e.g.).

Wait, what ? Care to elaborate ? The little time I’ve had with Lubuntu+LO installed from I haven’t seen any differences from what I’ve installed on Window$, so I’d love to know wtf.

Don’t worry! You will catch up.