If you haven't already, you might want to send this information to IDM support and see if they have anything to say. It seems they might have a decent chance of knowing (or finding out) what's going on between those two events.
Wondered what happen to the fast and light editor I used to like.
I've been using UltraEdit for years and I can't really put my finger on the exact version but I feel that the editor is getting heavy and loading speed becomes slower with time.
Just got a new Lenovo Yoga 900 laptop with Windows 10 , loading takes sometime 5 or 6 seconds, compare this to a free editor like Notepad++ and the difference becomes clear. Now, its true that UltraEdit is full of wonderful capabilities, but a code - text based editor should be as fast as possible as for the most parts we use it for very simple editing tasks.