In the case of stress-ribbon bridges, it is very important to consider also that, at the levitation stage, the initial cable-free hanging phase, might require, similar to the suspension bridges, for the numerical mathematical model, some additional constraints for the several cable connecting nodes to include compatibility about how a cable element behaves in a tridimensional structure. Therefore, cable nodes need fixation of all rotations for their beginning and end nodes, as shown in the picture below. This can be achieved by creating two different node series, one for the initial structure with only the cables, and another one for the deck and the composite structure. Then, for the cables, the nodes need to be fixed at Analyzer \ Structure \ Node Data \ Node Supports, as shown in the screenshot below. Note that only CMx, CMy, and CMz, are restrained and Cx, Cy, and Cz are kept free. Also, the first and the last nodes are free, including the rotations, allowing for the deflections.
More information can be found at the link below, by similarity, for Suspension structures.