1. I don't get the target of your model?
2. Assigning the same material to both 3D and 2D elements does not make much sense (choose Idealisation: Plane Stress or Plane Strain at the Element Geometry tab for membranes). However, if I remember correctly, if you use a 3D material for a 2D element, it gets interpreted like Plane Stress with 1m thickness - is that your intention?
3. Having several separate structures in a single model is not something the numerical solution is designed for.
4. If you only have line supports on 1 edge, the rotational DoF around that edge remains free - a rigid-bopdy motion mode unblocked.
On meshing, I get the message:
Warning: condition 'Load_Force_for_Surface' has flag 'on face elements' and it is applied 'on body elements' for the entity 1
- I suppose this kind of load is only for Surfaces belonging to Volumes in a 3-dimensional model. Maybe Zdenek can explain?