THIS IS ONE OF THE FIRST CAD PRODUCTS I HAVE DOWNLOADED I INITIALLY DONLOADED REVIT BUT FOUND  ESTMEP 2017 TO BE A BETTER FIT FOR ME TO LEARN WITH (MAYBE THIS IS THE ISSUE DONT KNOW) BUT I HAVE TRIED TO DOWNLOAD  ELECTRICAL DEVICES AND MATERIAL AND CANT GET PASSED THIS ERROR MSG   INVALID SIGNATURE: WEB CONNECT PLEASE HELP   THIS IS A STUDENT VERSION