We clearly mentioned there are some manual works for migrate data, we discussed it in our site and also in wp.org forum but we did all this to make it better.
Look, I love the plugin and the Download Manager team has done great work. But the perspective in the message above is mypotic. Your plugin has been downloaded 820,742 times. How many of those users do you think ever visit the plugin page or read the support forum? 10? 50? 100? Posting a note in the support forum does NOT reach your user base. May want to rethink how you communicate important messages like the need to migrate data.
Thanks, and I do enjoy the plugin.