Custom Ninja Forms PHP snippet to set maximum file upload limit message – Easily restrict file uploads with customized user notification in Ninja Forms plugin for WordPress.

ninja-forms-file-upload-limit-text-translate.php

<?php
// Customize the "Max x files are allowed" message in Ninja Forms File Uploads
add_filter( 'ninja_forms_uploads_js_strings', 'custom_ninja_forms_uploads_js_strings' );

function custom_ninja_forms_uploads_js_strings( $strings ) {
    // Change default message to German: "Max %n Dateien sind erlaubt"
    $strings['file_limit'] = __( 'Max %n Dateien sind erlaubt', 'ninja-forms-uploads' );

    return $strings;
}