It appears this issue arises when using

mix.styles 

All other commands work fine

Anyone have any suggestions?

where is your gulpfile.js ? post it here

Here is a stripped down copy. The issue i noticed was at the mix.styles command.

var elixir = require('laravel-elixir');
 
elixir(function(mix) {
    mix.less(['global/bootstrap.less','global/bootstrap-extend.less'],'public/css/output/bootstrap.css');
    mix.less('topbar/site.less', 'public/css/output/site.css');
 
    //Pages
    mix.less('pages/profile.less', 'public/css/output/profile.css');
    mix.less('pages/media.less', 'public/css/output/media.css');
          
    mix.scripts([
                 'vendor/formvalidation/formValidation.min.js',
                 'vendor/formvalidation/framework/bootstrap.min.js',
                 'vendor/matchheight/jquery.matchHeight-min.js',
                 'vendor/jquery-wizard/jquery-wizard.min.js',
                 'global/components/jquery-wizard.min.js'
                 ],
                 'public/js/output/wizard.js');
 
     
//  //Landing
    mix.styles([
                 'landing/animate.less',
                 'landing/landio.less',
                ]
              , 'public/css/output/landing.css');
     
    mix.scripts([
                 'landing/landio.min.js',
                 'vendor/holderjs/holder.js'
                 ],
                 'public/js/output/landing.js');
 
 
    // Core
    mix.scripts([
                 'vendor/bootstrap/bootstrap.min.js',
                 'vendor/animsition/animsition.min.js',
                 'vendor/asscroll/jquery-asScroll.min.js',
                 'vendor/mousewheel/jquery.mousewheel.min.js',
                 'vendor/asscrollable/jquery.asScrollable.all.min.js',
                 'vendor/ashoverscroll/jquery-asHoverScroll.min.js',
                 ],
                 'public/js/output/core.js');

    mix.version([
                 'public/css/output/landing.css',
                 'public/css/output/bootstrap.css',
                 'public/css/output/site.css',
                 'public/css/output/plugins.css',
                 'public/css/output/profile.css',
                 'public/css/output/media.css',
                 'public/css/output/asspinner.css',
                 'public/css/output/wizard.css',
                 'public/css/output/rating.css',
                 'public/css/output/bootstraptouchspin.css',
                  
                 'public/js/output/landing.js',
                 'public/js/output/extra.js',
                 'public/js/output/ie9.js',
                 'public/js/output/ie10.js',
                 'public/js/output/core.js',
                 'public/js/output/media.js',
                 'public/js/output/bootstraptouchspin.js',
                 'public/js/output/plugins.js',
                 'public/js/output/asspinner.js',
                 'public/js/output/wizard.js',
                 'public/js/output/rating.js',
                 'public/js/output/templatescripts.js']
    );
});