all galleries disappeared

Do you mean this page: https://www.claudepauly.net/photography-random Right ?

Did you install some new plugins ? or maybe did you change or modify blog theme ?

Did you make some changes in gallery settings before galleries gone ? Did you move your page with gallery from server to server ?

Yes that one and also
https://www.claudepauly.net/scribblarium
https://www.claudepauly.net/pics

No I haven’t changed a thing, they just stopped working. I might have updated the plugin itself at some point though.

So what now? is there a solution?
Thanks.

I had the same problem in the past. The reason was in external lightbox plugin which was installed after robo gallery installation.
After suggestion of the robo gallery support we just switch jQuery settings in general gallery settings (in left side menu of the wordpress admin section / settings sub menu below Robo Gallery menu item).
Also do not forget to turn off cache. Couple of times cache was the reason of incorrect load of the modifications. When you configuring gallery you need to turn off cache and enable it back when you finish configuration.

thanks ellopezt, but I tried every possible setting, disabled all other plugins etc, nothing works,

Ok nevermind, I just deleted it and installed another gallery. Too bad, as I liked Robo and its intuitive functionalities.

There’s could be few reasons of such gallery behavior. It’s jQuery conflict, lost images or some configurations problems.
In the case if you try to play with gallery optimization options with no luck. We should make sure that you didn’t delete gallery images by accident.
Another tip: make sure that you didn’t enable hide self images option in robo gallery general settings.