2nd order effects must meet the conditions given in the regulation. If this is not provided on any story, the program warns you. However, in some projects, stories that do not have a physical connection with the main base story, such as stair landings, ground story eaves, are defined as single console story. If these stories are defined as separate rigid diaphragms, it will not be possible to provide a 2nd order indicator value. If you select "Create a rigid diaphragm" option from the slab properties and analyze again, your problem will be solved.