just download another FS and extract it.
Don't need to be the same FW, but need to the a FS made to your phone.
I mean to your model or type.

Eg.

I can use a menu.ml from FW R4JA011 or any other FW made to w200.

The same to you.
You can extract the FS you another FW made to the W830.

sorry for my bad english.