When my elementary students sign in and try to select an activity on Hour of Code, they are shunted into a teacher’s view of the selections wherein they can only select either to view or to assign any of the activities. And when they click on "Assign’ they are informed that they need a teacher account to give assignments. This problem doesn’t seem to happen on activities they have already begun, to which they are returning; it’s just when they go to hour of code selections, either from the links on their dashboard or from those in the curriculum catalog. But the vast majority of my students are effectively barred from hour of code. Why is this happening? is it a bug? How can I fix it?