Hello, In the project, after marking the sub-basement curtain on the curtains and increasing the number of modes (250), there is no problem when analyzing. However, if there is no special reason, I can suggest that you add columns between the openings in the 1 and 12 axles of the outer frame and make the frame continuous on these axes. You entered only snow load as roofing load. It may have been overlooked. good work.