hi guys! i 'm a new user of openstudio and energy plus and i 'm facing a problem. i have made my model in open studio and i would like to export the idf file so that i can assign materials to surfaces, create schedules etc. but, while i press the export button i get this error ''Error: No construction for either sub surface 'Sub Surface 594', and 'Sub Surface 645'' for maybe every surface i have designed! should i make something to correct this or it will be solved by creating materials and assigning them to my surfaces in energy plus?