Scss files end up empty

[JonWallsten]

Hi!
I have a bunch of SCSS file that I process and save as normal CSS-files. When I process them I add en external source map file. Later I concat the generated CSS-files and merge the sourcemaps with your plugin. I have used console log to make sure the script is working, and I can see the original and generated lines. It seems okey to me. However the files end up empty in Chrome Dev Tools when i check. JS/CSS works fine.

So here's the chain:
a.scss -> a.css & a.css.map
b.scss -> b.css & b.css.map

[a.css, b.css] -> bundle.css|bundle.css.map

Source maps contains the link between scss and css source before concatenated.
Any ideas? Thanks!