The problem is as described in the subject. As per the following post, if the structure is in equilibrium instability error should not arise.https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/8063/lifting-analysis
I have attached the model. Can you please advice on the cause of instability.
Staad Version: 21.00.02.43FundamentalLiftingTest.std