File upload dropzone - submit button not working

Followed tutorial on creating a basic Dropzone file upload
and everything went well except when testing Upload your File the submit button appears to fail. Double and triple checked procedure. Must be missing something. Chrome debug reports the following error?:
Uncaught (in promise) Error: A listener indicated an asynchronous response by returning true, but the message channel closed before a response was received. ------------------- Any help would be appreciated.

Please post your form code and a screenshot of the Network > XHR tab errors if any, after submitting the form.

<form id="form1" is="dmx-serverconnect-form" method="post" action="dmxConnect/api/upload_files.php">
					<input id="file1" name="file1" type="file" class="form-control" multiple="true" is="dmx-dropzone" accept=".jpg, .png, .pdf, .ai, .eps, ">
					<button id="btn1" class="btn btn-primary" 
type="submit">Upload Files</button>
				</form>

XHR on console says
Uncaught (in promise) Error: A listener indicated an asynchronous response by returning true, but the message channel closed before a response was received

And how does the dropzone looks in the browser? Is it also nested in a form? Maybe show the html code as well.

seems to display well - all good except when i select submit nothing happens.
I kept the upload form basic to get it worjkimng vbefore trying to add other features - html of page is below

<!doctype html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta name="description" content="Upload large print files to Mr. Print using our easy dropbox link on this page. To help reduce spam and prevent hacing, call us for the access code.">
	<link rel="canonical" href="https://mrprint.ca/upload.php" />
	<title>Upload your File</title>
	<script src="dmxAppConnect/dmxAppConnect.js"></script>
	<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
	<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN" crossorigin="anonymous">
	<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
	<script src="dmxAppConnect/dmxBootstrap5Navigation/dmxBootstrap5Navigation.js" defer=""></script>
	<link rel="stylesheet" href="https://pro.fontawesome.com/releases/v5.15.4/css/all.css" integrity="sha384-rqn26AG5Pj86AF4SO72RK5fyefcQ/x32DNQfChxWvbXIyXFePlEktwD18fEz+kQU" crossorigin="anonymous">
	<link rel="stylesheet" href="style.css" />
	<link rel="stylesheet" href="bootstrap/5/css/bootstrap.min.css" />
	<script src="dmxAppConnect/dmxS3Upload/dmxS3Upload.js" defer></script>
	<link rel="stylesheet" href="dmxAppConnect/dmxDropzone/dmxDropzone.css" />
	<script src="dmxAppConnect/dmxDropzone/dmxDropzone.js" defer></script>
	<link rel="stylesheet" href="dmxAppConnect/dmxValidator/dmxValidator.css" />
	<script src="dmxAppConnect/dmxValidator/dmxValidator.js" defer></script>
</head>

<body is="dmx-app" id="index">
	<?php include 'header.php';?>
	<div class="container">
		<div class="row">
			<div class="col-xl-6">
				<h1>Upload your Files here!</h1>
				<p class="lead">Call or email us for the access code.&nbsp;</p>
				<p class="lead">Your files will be uploaded to a secure site. Thanks for choosing Mr. Print</p>
			</div>
		</div>
		<div class="row">
			<div class="col">
				<form id="form1" is="dmx-serverconnect-form" method="post" action="dmxConnect/api/upload_files.php">
					<input id="file1" name="file1" type="file" class="form-control" multiple="true" is="dmx-dropzone" accept=".jpg, .png, .pdf, .ai, .eps, ">
					<button id="btn1" class="btn btn-primary" type="submit">Upload Files</button>
				</form>
			</div>
		</div>
	</div>
	<?php include 'footer.php';?>
	<script src="bootstrap/5/js/bootstrap.bundle.min.js"></script>
</body>

</html>

George i posted info requested - so just following up to see if you have a chance to look at my issues. still having problem
Norm

actuall - i will check with my server and get them to look at folder permissions first

  • sorry just thought of that - re below

So I started all over again from scratch and the submit button on form seems to work - but no file goes to me chosen path - nothing is in that folder? /assets/uploads
chrome debug says files transferred and


doesnt show errors just says issue: event listener is deprecated.

webpage is located at

How is your File upload step set up in your Server Action?

all working now it was folder permisions on my server
thanks for reviewing for me!