Hei,
Thanks for your answer, I deactivated the plugins and it seems that Polylang it’s the one that is conflicting in some way.
I googled the conflict between Polylang and the revolution slider and it seems that other people had the same issue.
https://kaptinlin.com/support/discussion/11508/plugin-polylang-problem-with-slider-revolution/p1
Any ideas why? Can I make a quick fix or something like that?
If not how do you recommend that I should do the internationalization?
Thank you very much,
Merca