home folders

I work at a school and have created user accounts. I have created folders, based on the student's graduating year, and have put these home folders in their designated sub folder. For some reason, the home folders cannot be mounted. For example: I cannot mount the user's home folder if the path is "afp://<server>/Students/GY2017". However, putting these home folders in the shared folder works just fine. I am using a lion server.