You have changed you War Base during war, did You?
They are distributing the War loot with heavy Mortars, and that was calibrated to hit the position of your Command Post at the beginning of the war. Well as the War has ended your Command post's position has changed and the heavy mortar hit a building without any resource capacity.
OK, this is a known bug. If you change your actual war base layout during the War, then it might happen, that the War Loot is not delivered...