I just installed it a couple of days ago myself. I'm no pro at this but I bet you have a pathing issue as I did. My suggestion to you is to focus(fully understand) where all the MDB drag and drop files reside. Specifcally the ADDONS, CSS and the JS folders.
Here is what I did - After downloading plugin, I unzipped the MDB_fileupload file within my web project and changed the path for the header scripts and links as well as the footer scripts to reflect the correct path within my HTML or PHP page calling the functions.
For example, lets say my website is called mywebsite.com then the install path should be
https://mywebsite.com/MDB_fileupload, or localhost/MDB_fileupload or /var/www/html/MDB_fileupload. All three mean the same thing basically, so hopefully you get what I am saying.
The header:
<linkhref="MDB_fileupload/css/bootstrap.min.css"rel="stylesheet">
<linkhref="MDB_fileupload/css/mdb.min.css"rel="stylesheet">
The footer scripts:
<scripttype="text/javascript"src="MDB_fileupload/js/jquery-3.3.1.min.js"></script>
<scripttype="text/javascript"src="MDB_fileupload/js/popper.min.js"></script>
<scripttype="text/javascript"src="MDB_fileupload/js/bootstrap.min.js"></script>
<scripttype="text/javascript"src="MDB_fileupload/js/mdb.min.js"></script>
<scripttype="text/javascript"src="MDB_fileupload/js/addons/datatables.min.js"></script>
<scripttype="text/javascript"src="MDB_fileupload/js/addons/mdbFileupload.js"></script>
Please let me know if this works for you, as this is the first question I have ever attempted to answer in this forum, and I hope it helped.
I have a problem to, I want to remove the built in delete button for a specific reason. It is so embedded in the java script I cant find it. I have been waiting for over a day with 12 views and 0 answers.