Is prayer valid in a mosque in which the decorations and ornaments display shapes resembling crosses, and is it obligatory to demand their alteration?

There is no objection to praying in the aforementioned mosque. The prayer is valid, and the presence of pictures or crosses does not affect its validity. If prayer is valid in a church, albeit disliked, then it is valid in a mosque even with the presence of cross images. Those responsible for the mosque must remove as many cross images as possible, provided that no greater harm results from their removal. They are not to be blamed for any remaining crosses after they have exerted their effort to remove them, for Allah Almighty says: "Allah does not burden a soul beyond its capacity."