Sharing Cart locking down edit functions after update

After updating Sharing Cart to version 2019012000, the plugin is preventing all edit functions from loading properly, as shown here: https://www.screencast.com/t/P0NG9zqyOW

Looks like some kind of JS problem.

• Here's the error reported by the server: https://www.screencast.com/t/WKjAmyM0

• Here's the error reported on the FireFox debugging console: https://www.screencast.com/t/wYWqtpLds9JU 

The strange thing is that this problem exists on our production server, but I can't seem to replicate on our test site.

We're running Moodle 3.5.4.

Wondering if anyone has come across this problem.

Thanks,

Fernando