Gulp unknown error anyone can help?

Question

JavaScript

Please help me, I've been struggling for a few days now and can't find a solution to this problem.
When writing code in a sass file, browser sync stops working and other modules, when launched through the console, gives the following message:

var gulp         = require('gulp'),
    sass         = require('gulp-sass'),
    autoprefixer = require('gulp-autoprefixer'),
    cleanCSS     = require('gulp-clean-css'),
    rename       = require('gulp-rename'),
    browserSync  = require('browser-sync').create(),
    concat       = require('gulp-concat'),
    uglify       = require('gulp-uglify');

gulp.task('browser-sync', ['styles', 'scripts'], function() {
    browserSync.init({
        server: {
            baseDir: "./app"
        },
        notify: false
    });
});

gulp.task('styles', function () {
  return gulp.src('sass/*.sass')
  // output non-minified CSS file
  .pipe(sass({
    includePaths: require('node-bourbon').includePaths
  }).on('error', sass.logError))
  .pipe(autoprefixer({browsers: ['last 15 versions'], cascade: false}))
  .pipe(gulp.dest('app/css'))
  // output the minified version
  .pipe(cleanCSS())
  .pipe(rename({suffix: '.min', prefix : ''}))
  .pipe(gulp.dest('app/css'))
  .pipe(browserSync.stream());
});

gulp.task('scripts', function() {
  return gulp.src([
    './app/libs/modernizr/modernizr.js',
    './app/libs/jquery/jquery-1.11.2.min.js',
    './app/libs/waypoints/waypoints.min.js',
    './app/libs/animate/animate-css.js',
    './app/libs/Magnific-Popup/jquery.magnific-popup.min.js',
    './app/libs/animateNumber/jquery.animateNumber.min.js',
    './app/libs/equalHeights/equalHeights.min.js',
    './app/libs/owl-carousel/owl.carousel.min.js',
    './app/libs/selectize/dist/js/standalone/selectize.min.js',
    ])
    .pipe(concat('libs.js'))
    .pipe(uglify()) //Minify libs.js
    .pipe(gulp.dest('./app/js/'));
});

gulp.task('watch', function () {
  gulp.watch('sass/*.sass', ['styles']);
  gulp.watch('app/libs/**/*.js', ['scripts']);
  gulp.watch('app/js/*.js').on("change", browserSync.reload);
  gulp.watch('app/*.html').on('change', browserSync.reload);
});

gulp.task('default', ['browser-sync', 'watch']);

here is my sass file header.sass

@import bourbon
@import fonts.sass
@import vars.sass

body
  font-size: 16px
  min-width: 320px
  position: relative
  line-height: 1.6
  font-family: "OpenSansRegular", sans-serif
  overflow-x: hidden
  color: #222

h1, h2, h3, h4, h5, h6,
.h1, .h2, .h3, .h4, .h5, .h6
  font-family: "OpenSansLight", sans-serif
  font-weight: normal

 h1
 	font-size: em(43)

 h2
 	font-size: em(34)	

 h3,h4
 		font-family: "OpenSansBold", sans-serif
 		text-transform: uppercase
 		font-size: em(17px)
h4
  font-size: em(15px) 		

.hidden
  display: none

.main-head	
  background-image: url(img/bg_top.jpg)
  background-size: cover
  background-position: center
  min-height: 100vh 

.mnu-line
  padding-top: 48px

.logo
  display: block
  width: 78px
  img
    width: 100%

nav
  ul 
    list-style-type: none
    padding: 0
    margin: 0

  li 
    display: inline-block

.main-mnu
  text-align: center
    > ul 
      > li 
        > a 
          display: block
          padding: 10px 18px
          color: #7e91a4

folder directory looks like this:

PS recently deleted everything and created a new project everything worked fine after implementing changes in sass files again the same problem appeared. What am I doing wrong I have no idea...

Answer 1

The problem is solved, the whole problem was in the sass file, namely in the .main-mnu class, after re-writing the code, the problem was solved.

Answer 2

put gulp-plumber will write errors to the console