Download button does nothing

Been using this plugin for a year with no problem. Just discovered that the download button stopped working. When the page loads, I get the following error in Chrome’s Developer area:

Uncaught SyntaxError: Unexpected token <
single.js?ver=4.9.1:6
Uncaught TypeError: $(…).scrollable is not a function
at HTMLDocument.<anonymous> (single.js?ver=4.9.1:6)
at i (jquery.js?ver=1.12.4:2)
at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4:2)
at Function.ready (jquery.js?ver=1.12.4:2)
at HTMLDocument.K (jquery.js?ver=1.12.4:2)
(anonymous) @ single.js?ver=4.9.1:6
i @ jquery.js?ver=1.12.4:2
fireWith @ jquery.js?ver=1.12.4:2
ready @ jquery.js?ver=1.12.4:2
K @ jquery.js?ver=1.12.4:2
==============================================
Support info
### Begin System Info ###

## Please include this information when posting support requests ##

Licensing Version: 1.0.8
Multisite: No

SITE_URL: https://nova-iris.net
HOME_URL: https://nova-iris.net

WordPress Version: 4.9.1
Permalink Structure: /%year%/%monthnum%/%day%/%postname%/
Active Theme: Ribosome 2.2.4

Registered Post Stati: publish, future, draft, pending, private, trash, auto-draft, inherit

PHP Version: 5.6.31
MySQL Version: Web Server Info: Apache

WordPress Memory Limit: 40M
PHP Memory Limit: 512M
PHP Upload Max Size: 512M
PHP Post Max Size: 512M
PHP Upload Max Filesize: 512M
PHP Time Limit: 1800
PHP Max Input Vars: 1000
PHP Arg Separator: &
PHP Allow URL File Open: Yes
WP_DEBUG: Disabled

WP Table Prefix: Length: 2 Status: Acceptable

Show On Front: page
Page On Front: IRIS as Good as Ever (#2)
Page For Posts: (#0)

WP Remote Post: wp_remote_post() works

Session: Enabled
Session Name: PHPSESSID
Cookie Path: /
Save Path: /var/cpanel/php/sessions/ea3
Use Cookies: On
Use Only Cookies: On

DISPLAY ERRORS: N/A
FSOCKOPEN: Your server supports fsockopen.
cURL: Your server supports cURL.
SOAP Client: Your server has the SOAP Client enabled.
SUHOSIN: Your server does not have SUHOSIN installed.

##COMPATIBILITY

WordPress Version 4.9.1 OK
Permalinks enabled Yes OK
PHP Version 5.6.31 OK
mbstring support On OK
intl support On OK
PHP Memory Limit 512M OK
PHP Max Upload Size 512M OK
PHP Max Post Size 512M OK
PHP Max Execution Time 1800 OK
PHP cURL On OK
PHP allow_url_fopen 1 OK

##ACTIVE PLUGINS:

CM Download Manager: 2.5.14
Free & Simple Contact Form Plugin – Pirateforms: 2.3.0
Front End PM: 6.2
iThemes Security: 6.7.0
Simple Links: 4.3.0
Ultimate Member: 1.3.88
WP-SpamShield: 1.9.21
### End System Info ###

The page I need help with: [log in to see the link]