Sorry to hear that it’s not working for you. To be very honest, we didn’t get any other report about incompatibility with WP 4.2. We did check yesterday again when you post a message in our comment section. But we will check, why it’s not working for you.
It could be sort of plugin conflict. Is it possible for you to deactivate all other plugins except the Menu Manager and activate default WP theme (2015 or 2014) and then check what happens?
If you still have issues in vanilla stage, then we will need to login and check. In that case, please send your admin username and password (or you can create a temporary account for us) and post here. IMPORTANT: When you post secret info, please make sure you check the box for “Set as private reply” so that no one except you and us can see this information.