Error on Compile

[doubledevwp]

Sorry if this is a noob thing, but I am receiving errors ( on multiple files ) that include the following when compiling:

Error: no mixin named prefix

   Backtrace:
   	sass/c:\aaa\bbb\ccc\admin\res\css\productionsummary.scss:4
    on line 4 of sass/c:\aaa\bbb\ccc\admin\res\css\productionsummary.scss

@include prefix(box-sizing, border-box); ----------^

not sure why i this path is different:

Error: File "c:\aaa\bbb\ccc\portal\public\res\css\site.css" not found on line 10 of sass/c:\aaa\bbb\ccc\admin\res\css\style.scss

@import "site.css"; --------^

Other people working on the same project in their editors ( JetBrains ) are not receiving any issues.

[capegreg]

I'm getting this error on compile, but the include is working correctly.

@include my-image('aaa.jpg'); -----------^