When calculating a simple cable structure (concentrated load 10 kN in the middle of the cable), I obtain plausible support and cable forces.
The deformation, however, is not plausible (see figure 1).
What might be the reason for this?
This graphical representation results because of the display factor for the deformations.
By reducing it to 1, you obtain realistic deformation.
To specify this factor, use the panel. The panel appears (usually on the right) if the results are shown. If necessary, select it on the menu "View -> Control Panel."
This allows you to better see that the force in the middle results in a stretching of the cable. The stretching leads to an upward shifting of the outer nodes.