When you are importing a classroom on Windows 8 or 8.1 machines you must completely disable User Account Control and edit or add the following registry key value on the teacher for it to prompt for which type of class you wish to create correctly.  

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]

EnableLUA"=dword:00000000

After this restart and it should function as intended.