In Local Administration -> Carousels when you go to edit a carousel there is an active translation button for the Name field (which I think is the only field that displays as part of the carousel to the public).
In Server Administration -> Carousel Types the Apply Translations button is active.
In Local Administration -> Carousel Library Mappings the Apply Translations button is still grayed out but I don't think there are any translations that should be applied to that interface via the staff client since it is pulling the info about the carousels from Local Administration -> Carousels.
This might be resolved in 3.9.
In Local Administration -> Carousels when you go to edit a carousel there is an active translation button for the Name field (which I think is the only field that displays as part of the carousel to the public).
In Server Administration -> Carousel Types the Apply Translations button is active.
In Local Administration -> Carousel Library Mappings the Apply Translations button is still grayed out but I don't think there are any translations that should be applied to that interface via the staff client since it is pulling the info about the carousels from Local Administration -> Carousels.