Re: steel bungalow lover problem Hello; 10.57 only beta users, sorry for the missing information. When it says stiffness error, the program does not say to accept the system as rigid, there is a relative insufficiency of story drift, so you need to increase the stiffnesses of the elements. In other words, you should increase the section, although the steel elements provide the PMM ratio, the structural design will not be made properly unless the relative displacement required by the earthquake regulation is provided. First, increase your column sections and increase lateral stability.