Avoid virtual and physical products combination in WooCommerce cart

I have been searching for this for a long time but never seemed to find a possible solution.

Does anyone see any solution of how to allow only physical or only virtual products in one Woocommerce cart? Possibly, with a notice popping up when the customer tries to add a combination of both virtual and physical and disallowing the combination - or making sure that the combination cannot appear in one cart.

Having a combination in the order keeps causing errors..

Please help.

The following will avoid to combine physical and virtual products in cart:

// Check cart items and avoid add to cart
add_filter( 'woocommerce_add_to_cart_validation', 'filter_wc_add_to_cart_validation', 10, 3 );
function filter_wc_add_to_cart_validation( $passed, $product_id, $quantity ) {
    $is_virtual = $is_physical = false;
    $product = wc_get_product( $product_id );

    if( $product->is_virtual() ) {
        $is_virtual = true;
    } else {
        $is_physical = true;
    }

    // Loop though cart items
    foreach( WC()->cart->get_cart() as $cart_item ) {
        // Check for specific product categories
        if ( ( $cart_item['data']->is_virtual() && $is_physical )
        || ( ! $cart_item['data']->is_virtual() && $is_virtual ) ) {
            wc_add_notice( __( "You can't combine physical and virtual products together.", "woocommerce" ), 'error' );
            return false;
        }
    }

    return $passed;
}


// For security: check cart items and avoid checkout
add_action( 'woocommerce_check_cart_items', 'filter_wc_check_cart_items' );
function filter_wc_check_cart_items() {
    $cart = WC()->cart;
    $cart_items = $cart->get_cart();
    $has_virtual = $has_physical = false;

    // Loop though cart items
    foreach( WC()->cart->get_cart() as $cart_item ) {
        // Check for specific product categories
        if ( $cart_item['data']->is_virtual() ) {
            $has_virtual = true;
        } else {
            $has_physical = true;
        }
    }

    if ( $has_virtual && $has_physical ) {
        // Display an error notice (and avoid checkout)
        wc_add_notice( __( "You can't combine physical and virtual products together.", "woocommerce" ), 'error' );
    }
}

Code goes in functions.php file of your active child theme (or active theme). Tested and works.