first of all I apology for my delay but the last week I was really busy and I could not reply.
In order to speak about your question, the problem you met I met too in the same way. I’ve noticed the model <Solution Algorithm Type> is <Newton> algorithm but the warning is referred to < KrylovNewton> that failed. I tried to change the Algorithm Type but always it turns back to KrylovNewton.
When you improve the strength of both concrete and steel you have to run at first Gravity case and then lateral. This way the problem remains.
Anyway in the <Animate Response> you can sees the model deformation developing in the right way while the <Plot Response> show always the problems I’ve reporting.
Keep in touch and let me know if you have any news about Example 4, please.