Thanks offspring, actually I don’t think it was the theme because I tried to switch the theme, didn’t help.
But the strange thing, is that the day after, everything was fine ?!?
I had tried with different browser, different computers… so I guess it had to do with one of my plugin, there are quite many in there ?? but I don’t really know. Maybe something like Kaltura since it’s a service, maybe they where down and that crashed my WordPress.
I don’t know, not very comforting, but it works for now so… it’s gonna be a mystery until it happens again ??