Your save-file must by corrupted, at least my AE5LE have imported my old profiles fine.(Aquasuite 2015 v4 -> Aquasuite 2015 v6 FW200x ->2003)
I had four different profiles. Actually, I used all of them. And I saved all of them just a couple of weeks ago with the last thing I updated on them.
Now I can't get any of them imported. I've tried them all.
In this PC I have an Aquaero 6 PRO and a Farbwerk USB version. I haven't tried in other PC that has an AQ5LT, Farbwerk USB and Aqualis reservoir with fill level sensor because I do not want to lost that PC's configurations as in this one.