can not save answer texts in quizzes and content in course section

Hello,

I can not can not save answer texts in quizzes， whenever it is published or not.

and can not same content in course section once it was published， that means the content can saved only at first time, but can not be saved when it is reedit after it was published, so two question here:

1.I am just wondering whether it is support MU sites?
2.Any compatible problem with chinese?

or what I misunderstand or did wrong setting?

Thanks

Alex