Koala does not compile the main file and how to fix it?

Question

Layout

There are files:
1. style.sass - which compiles and collects all files
2. _header.sass
3. _menu.sass
well, etc. each block has its own file
. And the problem is that when you save _header.sass, style.sass is not recompiled. How to fix it? Maybe there is no such trouble in the galle? Tell! Thank you!