Owen,
I have not found a solution yet for amjadsheen, but for now you could go back to an earlier version of Media Library Plus. Here is how to do it. Deactivate Media Library Plus, Active Media Library Plus Reset and run Reset Database. You want to do this with the current version of Media Library Plus since the reset plug was modified after version 3.0.6. After the reset you can delete the Media Library Plus plugin and then download version 3.0.12 from this page, https://www.ads-software.com/plugins/media-library-plus/developers/ Install, activate version 3.0.12 and then visit the Media Library Plus page and it will rescan your folders. In many cases this has worked. This should get you running again.
After following these steps some users were successful in upgrading to the current version of Media Library Plus. But I would advise backing up your database before doing that so in case things did not work with current version you could easily undo the upgrade by restoring the database backup and replacing the version of Media Library Plus with 3.0.12 again.