AdminLTE v3 sidebar-menu Treeview.js error [Laravel 5.5]

Problem: The sidebar-menu on the AdminLTE page doesn't COLLAPSE. Browser console says it searches for a "Adminlte.min.js.map" file which does not exist.

Details: I am learning Laravel-5.5 + Bootstrap-4 + AdminLTE-3 The AdminLTE-3 starter page loads all fine with CSS and JS except for the "Treeview" function on the sidebar-menu.

My sidebar-menu code:

<!-- Sidebar Menu -->
        <nav class="mt-2">
            <ul class="nav nav-pills nav-sidebar flex-column" data-widget="treeview" role="menu" data-accordion="false">
            <!-- Add icons to the links using the .nav-icon class
                with font-awesome or any other icon font library -->
            <li class="nav-item">
                <a href="#" class="nav-link">
                <i class="nav-icon fas fa-tachometer-alt"></i>
                <p>
                    Dashboard
                </p>
                </a>
            </li>
            <li class="nav-item has-treeview menu-open">
                <a href="#" class="nav-link active">
                <i class="nav-icon fas fa-cog"></i>
                <p>
                    Management
                    <i class="right fas fa-angle-left"></i>
                </p>
                </a>
                <ul class="nav nav-treeview">
                <li class="nav-item">
                    <a href="#" class="nav-link active">
                    <i class="fas fa-circle nav-icon"></i>
                    <p>Active Page</p>
                    </a>
                </li>
                <li class="nav-item">
                    <a href="#" class="nav-link">
                    <i class="fas fa-circle nav-icon"></i>
                    <p>Inactive Page</p>
                    </a>
                </li>
                </ul>
            </li>
            <li class="nav-item">
                <a href="#" class="nav-link">
                <i class="nav-icon fas fa-th"></i>
                <p>
                    Simple Link
                    <span class="right badge badge-danger">New</span>
                </p>
                </a>
            </li>
            <li class="nav-item">
                <a href="#" class="nav-link">
                <i class="nav-icon fas fa-user"></i>
                <p>
                    Profile
                </p>
                </a>
            </li>
            <li class="nav-item">
                <a href="#" class="nav-link">
                <i class="nav-icon fas fa-power-off"></i>
                <p>
                    Logout
                </p>
                </a>
            </li>
            </ul>
        </nav>
        <!-- /.sidebar-menu -->

my Package.json code

{
    "private": true,
    "scripts": {
        "dev": "npm run development",
        "development": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
        "watch": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
        "watch-poll": "npm run watch -- --watch-poll",
        "hot": "cross-env NODE_ENV=development node_modules/webpack-dev-server/bin/webpack-dev-server.js --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
        "prod": "npm run production",
        "production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --no-progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
    },
    "devDependencies": {
        "@fortawesome/fontawesome-free": "^5.13.0",
        "axios": "^0.17",
        "bootstrap": "^4.0.0",
        "cross-env": "^5.1",
        "jquery": "^3.2",
        "laravel-mix": "^1.0",
        "lodash": "^4.17.4",
        "popper.js": "^1.12.9",
        "vue": "^2.5.7"
    },
    "dependencies": {
        "admin-lte": "^3.0"
    }
}