compilation - Empty theme.css when trying to use original Bootstrap 3 files -

i tried adopt air theme insinde current ip. problem resulting theme.css stays empty, ithink due compilation error.

i have replaces original less files of theme inside assets/less-subfolder twitter bootstrap less files.

as include more ipcontent.less , variables.less (for example original bootstrap grid.less) resulting css file becomes empty.

does have idea? it's not file permission issue that's sure. missing variables suppose.

thank , cheers hamburg, thomas