Erreur GRUNT IMAGEMIN: impossible de lire la propriété 'Contenu' de non défini

GRUNT ImageMin jette l'erreur suivante lorsque j'essaie de l'exécuter: xxx pré>

voici mon package.json File: p>

module.exports = function(grunt) {

    grunt.initConfig({

        pkg: grunt.file.readJSON('package.json'),

        uglify: {
          build: {
            src: 'views/js/src/main.js',
            dest: 'views/js/build/main.js'
          }
        },

        imagemin: {
          dynamic: {
            files: [{
              expand: true,
              cwd: 'views/images/src/',
              src: ['**/*.{png,jpg,gif}'],
              dest: 'views/images/build/'
            }]
          }
        }

    });

    // 3. Where we tell Grunt we plan to use this plug-in.
    grunt.loadNpmTasks('grunt-contrib-uglify');
    grunt.loadNpmTasks('grunt-contrib-imagemin');

    // 4. Where we tell Grunt what to do when we type "grunt" into the terminal.
    grunt.registerTask('default', ['uglify', 'imagemin']);

};