Changing language in one item create an error 404 with Falang

Switching is done via Falang module.

By the way I found that the 3 xml content elements are not installed in the falang folder they are in the administrator/mediainstall_503f427fab60e folder is that normal? There are 3 xml files in the content element folder but they are older (still with Danan as author) Should I move the new one there?

I found the problem.

The French menu item was once translated by Falang but later changed to French so the translation was not anymore possible and visible.

To correct it: First change the language of the menu item to all, then delete the translation in Falang and finally set back the language of the menu item to the good language.

Et voilà

thanks for return