Student Login

I have about 7 students who must have had a teacher from last year use Classcraft.  I had all my students join a Google Classroom class that I only use to upload them to Classcraft.  All my students were easily uploaded except those 7.  There is an icon that is a triangle with an exclamation mark in the middle.  It says I have to use Teacher connect.  Is there a way to get them to join without having to use teacher connect?  I cannot get ahold of that teacher.  I think they may have retired?  There has to be a way to just have them start fresh.