Classrooms and instructors page not loading

Hi,

When i go to my client groups and then to learning i click on the task "Classrooms" and "Instructors".

For the page "Classrooms", if i click add the page opens but it doesn't load totally.

For the page "Instructors", if i click add the page opens..then i select a person and then the page doesn't load totally.

What can i do?

Thank you,

Francesco.