Going up to the chupah the Rabbi tripped on the steps that were covered with cloth and got hurt . Who is responsable for the damage, the owner of the Chuppa hall or the florist that takes care of the Chuppa?

If everything was installed properly and there was no obstacle, but the rabbi was not careful enough while he was walking, then neither is responsible for the damage, the owner of the Chupah hall nor the florist. If the Rabbi tripped on the stairs because the cloth was not installed properly, then it is considered a "pit in a private domain", and the question up for discussion is whether the digger of the pit must pay for the damage caused which in this case is the florist or does the owner of the Chupah Hall have to pay because of his responsibility for the damage done on his property. Jewish law in this case is; that when one digs a pit in his friend's property, as long as the property owner is not aware of the pit, the digger is responsible for all damage caused. As soon as the owner of the property finds out about the pit, he becomes responsible for the damage, but could then claim the damages from the digger (Rema Choshen Mishpat 410, 4 Sema ibid 8. Aruch Hashulchan ibid 3. Pitchei Choshen Laws of Nezikin 7, 8 and in footnotes). Therefore, the law in this case is that as long as the owner of the hall is unaware of the improperly installed cloth, the florist is responsible for any damage caused. Once the hall owner finds out about it and does not correct it, he becomes responsible for the damage and must pay the injured party. Nevertheless he can then claim the money from the florist.