У меня возникла такая же проблема после установки SCSS.Я исправил проблему, удалив ошибочные комментарии, которые рельсы помещают в заголовок.Вот так:
/*
* This is a manifest file that'll be compiled into application.css, which will include all the files
* listed below.
*
* Any CSS and SCSS file within this directory, lib/assets/stylesheets, vendor/assets/stylesheets,
* or vendor/assets/stylesheets of plugins, if any, can be referenced here using a relative path.
*
* You're free to add application-wide styles to this file and they'll appear at the top of the
* compiled file, but it's generally better to create a new file per style scope.
*
*= require_self
*= require_tree .
*/
#wrapper {
width: 980px;
margin: 0 auto;
}
Стало так:
#wrapper {
width: 980px;
margin: 0 auto;
}