Question

I just downloaded an intializr generated version of Bootstrap. I also installed SimpLESS to keep from having to constantly having to manually recompile my LESS files and to avoid using the in-browser compiler. SimpLESS however, refuses to compile the very basic style.css file in my directory. It spits up:

Result of expresiin style.less on 'e.message' [undefined] is not an object.

Note: “Expression” is indeed spelled the way it appears above.

My style.less file currently looks like this:

@import "bootstrap/bootstrap.less";

body {
  padding-top: 60px;
  padding-bottom: 40px;
}

@import "bootstrap/responsive.less";

Answer 1

I experienced the same issue, and the workaround for me was to not have nested @imports. I’m using SimpLESS 1.4 and Bootstrap 2.1.0 on Win7 and it works if your style.less file looks like this:

// CSS Reset
@import "reset.less";

// Core variables and mixins
@import "variables.less"; // Modify this for custom colors, font-sizes, etc
@import "mixins.less";

// Grid system and page structure
@import "scaffolding.less";
@import "grid.less";
@import "layouts.less";

// Base CSS
@import "type.less";
@import "code.less";
@import "forms.less";
@import "tables.less";

// Components: common
@import "sprites.less";
@import "dropdowns.less";
@import "wells.less";
@import "component-animations.less";
@import "close.less";

// Components: Buttons & Alerts
@import "buttons.less";
@import "button-groups.less";
@import "alerts.less"; // Note: alerts share common CSS with buttons and thus have styles in buttons.less

// Components: Nav
@import "navs.less";
@import "navbar.less";
@import "breadcrumbs.less";
@import "pagination.less";
@import "pager.less";

// Components: Popovers
@import "modals.less";
@import "tooltip.less";
@import "popovers.less";

// Components: Misc
@import "thumbnails.less";
@import "labels-badges.less";
@import "progress-bars.less";
@import "accordion.less";
@import "bootstrap/carousel.less";
@import "bootstrap/hero-unit.less";

// Utility classes
@import "utilities.less"; // Has to be last to override when necessary


//Needed if using fixed navbar 
body {
  padding-top: 60px;
  padding-bottom: 40px;
}
.sidebar-nav {
  padding: 9px 0;
}

// RESPONSIVE CLASSES
// ------------------

@import "responsive-utilities.less";


// MEDIA QUERIES
// ------------------

// Large desktops
@import "responsive-1200px-min.less";

// Tablets to regular desktops
@import "responsive-768px-979px.less";

// Phones to portrait tablets and narrow desktops
@import "responsive-767px-max.less";


// RESPONSIVE NAVBAR
// ------------------

// From 979px and below, show a button to toggle navbar contents
@import "responsive-navbar.less";